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Electronic Repair Questions/Answers and Testimonials- Part 17

By on October 12, 2008

My real interest is to repair lcd t.v’s.I have been repairing tv’s for many years.

Your monitor repair manual is great .

Have you written any lcd tv repair book ?

I am very interested to obtain a copy .

Thanks and regards


Hi R.B,
Thanks for the support of my ebook. As for the LCD TV repair ebook i wish i could write one but don’t have the chance to repair LCD Tv due to the fact that my nature of business is in computer repair. Have you try the LCD TV membership website by Mr Kent at ?


Hi Jestine

Greatly appreciate ur kind gesture in keeping me updated with current technical informations. I must confess, you have been of immense assistance and i truly appreciate this. Thank.



thank you very for being updated me your repair news letter regularly. i much appreciated your kindness and lots of time to send an email to every body.



Hi Jestine,

I must say you are really who you are by doing what you love impressed by your attitude not only on money issues to life issue also,i must say people like you are rare please keep it up it will take you far in life and i pray as you have remembered me in your good which before the end of the year i wish you total accomplishment b4 the end of the year. thanks for remembering me i really appreciate your concern and i will let you hear as i progress. am grateful for having you as a friend.

Ohai Samuel


Youth Impact society


Hi Ron,

Here are your questions and the answers:

1. These Viewsonic LCD monitors run from external 12VDC AC adapters
so much of the switching power supply stuff that is covered in the
ebook would not be useful.

I do cover how to test and repair ac adapter as well as the buit in SMPS.

2. These monitors use mainly tantalum capacitors and not
electrolytics so looking for blown electrolytics is not useful.

If the scalar IC and the LCD Controller IC have problem then there is no point of fixing it. However sometimes SMD components also could cause problem where my ebook is a good help for reference.

3. Your ebook talks about several specific brands of monitors but
nothing on Viewsonic.

The reason i did not mention the specific brand was because i want all my readers to grasp hold of how i solve the problem so that he or she can apply the method to solve any other brand of LCD Monitor. There is a saying “If i give a fish to you, you eat for a day. If i teach you how to fish you will eat for life!” This is the same concept apply to LCD Monitor repair. I can’t write a book of power problem for brand “A”, brand “B”, brand “C” and etc because in the market there are few thousands of brands of LCD Monitors. Then another subject of display shutdown for brand “A”, brand “B”, brand “C” and etc. I always believe this word “Once you know the principles you will know the rest”. I do provide email support to all of my buyers to help them step by step to solve their LCD Monitor problem.

Best regards,

Jestine Yong



My name is Peter, and I purchased from you a great course about LCD monitor repair, it is very useful, with practical examples.

Regards, Peter


Thanks for the great newsletters! As always they provide valuable information on repair that I have not seen anywhere else. Very well written, and profusely illustrated as well.

You are welcome!

My company is “downsizing”, so I have given some thought to perhaps opening my own repair business, maybe from home at first. I’m tired of working for others who mismanage the business, and lose customers. Was it scary at first for you to start your business?

No it was not scary because I’ve already have some good customers when i was working part time. That means my customers were big enough to pay me my salary then only i go ahead to set up one (with my partner). It’s not easy; it takes lots of commitment, your time and energy and hard work. I have few repair friends had closed their shop because they do not have enough customers and they never look for customers.

What words of advice would you give to someone in my situation?

Please read this article

With the bad economy here in the USA, and the “disposable consumer electronics” trend, is repair a viable means to make a living anymore?

You have to do lots of research first before you set up your own company. In my country, although I heard many are throwing their equipment, somehow i still got lots of equipment for repair.

I used to work for a company as a T.V. repair tech, but it was too much travelling and pressure, having to do up to 13 service calls a day, and they expect you to fix a TV in 20 minutes, with little or no parts on the truck!

That was a real pain man! In order to survive in this uncertainties and bad economy sweeping the USA i guess you have to really sit down and carefully think about your decision.

Thanks for your advice

No problem!

Best Regards,


Hi Mike,

Here is your questions and answers:

yes i read the reports, and have purchased the e book from your web site. We got it about 2 days ago. So far it has been informative helpful and very useful to reference. Thank you.

You are welcome and thanks for the support!

I am trouble shooting a Yaskawa Servo Amplifier “Servo Pack”. For a Mori
Seiki CNC Lathe. I narrowed problem down to single board and am testing
components for the bad one(s). Problem is motor gets overload while idle, or in motion. I tested many components and find a pair of 75k ohm wirewound resistors test and reading on analog meter shows 35k ohm and slowly rise to about 60k-70k in 30-40 seconds of time. so i am thinking tonight that maybe resistor is not resisting and current is flow to leg of motor, but without instruction to move, it holds position and so motor overload alarm is sent/comes out. so i will remove resistor from board and check out of circuit tomorrow. And go from there.

Hope to get a good news from you

i also have some problem in correctly testing the FET, it is N type. maybe it is bad , because i tested out of board, per your instruction and needle would rise, and hold position lifting red test lead, but only if my finger touch only middle pin, no effect when touch 2 pins with finger. situation with FET test. black on middle, red on right, no reading at any setting of ohm meter. touch 1 and 2 pin with finger needle rise. let go red lead, needle stays. remove finger needle fall. red on 3 black on 2 no reading, touch pin 2 only
needle rise. it seems the needle only rises, and stays when finger is on pin 2 and red is 3 and black on 2. so i am not sure, i will replace this regardless, i guess. i got the specs from NTE website for pin designation.

For some FET the moment you let go your finger the needle will straight away go down. Since you are getting a new one, you can compare both reading.

so that’s where im at on this fix. thanks for your book, it is big help in learning and troubleshooting down to circuit board level. many thanx.

You are welcome!


Hi Mr.Jestineyong,

I have problem with Philip GFL7D.So, I would like to get this projection tv service manual, if you have no problem. If you can please help me. Thanks kogyitinko

Hi Kogyitinko,
Sorry, i don’t carry any schematic for equipment. Please try

Online student,

Sir, Could you please explain me for what purpose use below items to understand technically. What does it work and their shapes?

1)-optoisolator ic 2)-, relay, 3) – SCR,


All these explanation can be easily found from google when you type in the keywords like:

what is scr

how scr work
and etc.



Hi Tracy,
Its an ebook and i don’t have the physical book form (ordinary book). That means, once you have paid through credit card you will be directed to a special download link where you can download my ebook. If you have other questions please do email me again. By the way i do not have the “troubleshooting tips” book. Thanks!


Hi P,

Thanks for the e-mail. How is going on over there?
I’m fine thank you.

I hope you are doing extremely good on your job and I wish I were there with you so I can learn how to repair all electronics.

Keep working on it and you will be successful soon.

I am voluntarily working in an electronic repair store, he is 15 years in service, there are a lot that he could not find the problem, especially the Plasma and LCD TV. He has never read the books and do not believe whatever in the books or internet either. He laughs at me whenever I read the ebook I bought from you. Sofar, I bought two from you. One is how to test the electronic components and the other one is how to repair lcd tv. I am very happy with your books.

Thanks for the support!

Well let me ask you for an idea. A 32 inches TV, when I turn it on is on, then when I turn it off and on again, it does not on, I unpluged the cord and plug it back again and turn on, it is on again, it keep doing the same thing all day long I guess. Remember when it is on it is on forever. I read your book and I told him that he should try to change the micro button, he said he did, but still have the same problem. Would you please give me an idea, so I can fix it in front of him.

From experience in smps repair, it could be start up resistors open circuit or the power ic itself have problem

For the Plasma and LCD TVs, I could not find even what board caused the problem, so he can change it. Well, I will wait until read all books I bought from you, I will be the member of how to repair those TVs. I want to be open my own bussiness next year. I will read all documents involves in the repairing.

Good to hear about your plan but for your information i does not own lcd tv and plasma repair membership website. It was from my repair friend mr Kent.


Dear Sir Jestine,

Im so happy to read your newsletter, I will assemble this Zener diode tester immediately. thanks a lot for this great info. I want to buy also the ESR meter but I could not afford as of now because I have some priorities to be financially settled 1st. If it is ok could I purchase it for 3 payments term? hehehe joke only sir. With lots of info-repair I am learning from your site sooner or later a lot more I will purchase from you. Take good care of your health and May God always be with you and protect you all the time.

Hi J,
Hope the project works well for you. Take your time to save the money and once you are ready you can just email me to get the ESR meter. More power to you and May God bless you richly too!


Hi, Mr. Yong

I got with an LG Philips model # 27pt543s37a, The problem is as soon as i plug it in power outlet the tv make a screaming ticking sound . What component that is bad?

Thank you


Hi leo,
You have to open up the tv and check it out as ticking sound can be any bad components. Try look for any bulged e-cap in the board.



I was delighted to here from you and will pleased to work in collaboration within you. I’m very interested in AC INVERTERS(12v Dc to 220v Ac with a battery charger incorporated 1000W and above. Here in Cameroon we always have power failure so I will be very happy if you can help me with any information. Concerning this if possible ship or sell them to me. These are some of the specifications;

DC to AC converter

Complete automatic battery charger.

– Power: 600W /800W / 1000W /1500W / 2000W /2500W

3000W /5000W about 12A

Thanks in advance, I look forward
to here from you again.

Hi S,

Sorry i do not have such information about AC inverters.


Do you have a book on LCD TV repair? I have had success with fixing the LCD displays and would like to learn about LCD TV repair.

Hi Danny,
Sorry i do not have ebook on LCD TV repair . Have you try to join my repair friend Mr KENT LCD TV REPAIR membership website at


Thank you sir for your kindness to give me reports.

i really a appreciate it. Can you help me for this monitor i am fixing? it has power but there was no display out put on it and also you cannot feel any oscillation from the picture tube or static like in the screen there is no feel of static on it. i check the horizontal transistor its reading is less than 100v and fluctuating. can you help for this one? thanks and more power!

Hi D,
Check whether the flyback internal capacitor have problem or not by visiting this link:


Hi Justine,

That’s very2 good equipment. Thank you for the idea and also the steps on how to build the zener diode tester. I hope it will help our current multimeter to check and identify electronic components.


Hi there Jestine

Thank you very much for your frequent newsletters and emails. I am really enjoying reading the latest electronic news. Although we are about 30 years behind in South Africa we are busy catching up. My business is still growing gradually and due to the fact that we also handle insurance claims we have no option but to expand our knowledge to the degree that we also repair appliances. We therefore have two running workshops at the moment. This is just a brief background to introduce our business. It is great to have friends so far away that are willing to share their skills in such an informal way.




Hi D,

Here are your questions and answers:

Yes I found that and signed up for the manual. Ill go through the manual and see if its something I can handle. Thanks for all the help.

You are welcome

I’ve come along way setting up shop to make some money on the side with your books, I took electronics about 20 years ago and have been in IT (computer repair and support, networking) for 22 years but bored with it, more interested in board level repair, much more interesting.

Yeah me too-electronic repairing is more interesting!

Wish I could find training on component level laptop motherboard repair. Could make allot of money repairing them with such a big market and the high rate of failure on the loose BGA’s and power SMD failures, hard to identify the failed power IC’s, the loose BGA video chips are easy to diagnose.

You can buy lots of cheap laptops and practice on your own.

Do you know of any info on diagnosing laptop motherboards to component level?

Heard of does sell laptop repair information but some of my members who bought it said the information is very basic.

Ill probably buy the membership for the TV repair, good market.

You have to test out the water

Seems with more practice the LCD repair will become easier, not too much to them. I’ve fixed several power supplies with shorted IC’s, diodes and mostly bad capacitors, the Atlas ESR and DSA testers are really nice,

Congrat on your successful repairs!

I purchased the cricket tester on eBay with no manual, you know where I can get a manual for it? The manufacturer wants 25 dollars for copy of it, the Super Cricket only cost me 50 bucks.

Sorry no idea about the manual.

Those tools you recommended sure do the job well, especially for someone with little experience as I have.

Continue to repair and expect good result with the help of those tools.

Thanks again for the help; your books have been very helpful getting me started.

No problem!

Best Regards,
Jestine Yong


Hi Jestine,

L.J Simon here from South Africa, many thanks regarding your e-books, I’ve read and enjoyed them very much. I believe that it’s a very resourceful product and really admire your contribution towards the
electronic repairing community.


Hi Johnny,

Here are your questions and answers:

Thank you for your fast email

No problem!

I like to learn repair work and do not known where to start off

Get my Testing Electronic Components ebook first as this ebook touch many basic and intermediate about testing electronic components. Once you are strong in testing electronic components, in fact you can actually start to do the electronic repair work.

Maybe to start with how to repair my own computer PC

Its your preference if you wanted to.

Is there a practical lessons ?

More information can be found at

How to get in touch with you ?

You can call my office at 603-62778522.

Best regards,

Jestine Yong


Hello Jestine

Thanks for been in touched you know what am still on able to get the Timer delay fuse replace for my Television. I don’t know if you can still be of help or if you can source it for. Hope your business is fine.

My regards,

Idowu Akinola

Hi Idowu,

Try to find from the list of electronic suppliers at


Hi Reden,

Here are your questions and answers:

Sir,its a privilege for me to view on your web site that really enhance my interest to view more. I am a newly electronic instructor with more than two years in teaching experience,but by profession i am a electronic repairer with my personal shop handle and authorized service center of Sharp.I admit that with in my 17 years experience as a repairer im still felt of my insufficiency on this field.I’m looking forward to every web site that can satisfy my emptiness until i got your site.I know that i am on the right track now where i have to spent my lot of hour on patronizing on your site.

Thanks that you liked my website

In view there to,can you help me to understand widely on digital electronics and update me on simple to comflex digital projects

The best to understand about digital electronics is to get the book by Flyod “Digital Fundamentals”.

and also update me on your different books,its price and how to avail it.

All of my books are ebooks (pdf files). That means once the payment is done you will get the download link and you can save the ebook into your computer. You then can read from the computer screen or print it out and bind it as a book.

Here are my ebooks:

I really thank you so much for having you.More power and God Bless.
You are welcome!


Hi Charlie,

Here are your questions and answers:

Hello, I am a big fan of your web-site. I would like to see more info on repairing color computer monitors.

Thanks! I wish i have some extra time to write it-currently trying to finish my fourth ebook.

I have a monitor that has a switch-mode power supply with the symptom of dead, no power. The CRT does not glow at the neck, and there is no discharge on the anode of the CRT. Fuse is good (so is the rectifier), the Horz. Output xister test good out of circuit, and I have about 150vDC at the collector. The board has no burn marks except under a 2watt(?) resistor. I removed it from the circuit and it is OPEN. I am writing because I have never seen a resistor with a color code like this one… this is the color-code:

—-[Black, White, Red Brown]—-

The brown code looks thicker than the other 3 codes, so I am assuming this
is a 1% tolerance resistor. What value could this be? I am not sure if a
code is missing between red and brown… (I do not think there is a code
there). But I have never come across a resistor that ever started with black

Can you help me?

Sometimes a constant heat could change the purity of the color. A yellow band could be like an orange band and etc. In your case i guess the white should not be the original colour. Assuming it has four color band then we have brown, red, white and black (ignore the black colour). now lets assume the white can be a brighter colour like orange and yellow. That’s mean you can start with 12 k or 120k to test it out first. Assuming if i were to repair that monitor, first i will check the resistor belong to what circuit and then compare it with a similar monitor schematic diagram and look for a common value (2 watt) in that particular circuit. Hope this helps!



No tengo información acerca de la reparación de tv de plasma. El sitio web tv de plasma es la reparación de pertenecer a la reparación de mi amigo el señor Kent y usted puede email él en fastrepairguide(at)

Saludos cordiales,


hola amigo jestine despues de mullo tiempo de escribo esta pequeña misiva quisiera saber mas detalles de ese istrumento azul cuales son sus vetajas de este medidor digital con pantalla puesto que yo compre el capachek ase mullo tiempo pero solo mido capasitores que tienen mucho tiempo abeses me mide bien y pero medi cuenta que ese era el problema porque cuando le cambie sesoluciono solo me sirve para medir filtro que tienen mucho uso de tiempo y cuando estan secos igual miden tamvien cuando estan crusados mas no puedo medir capasitores ceramicos quisiera tener mas conosimiento sobre este instrumento que levi en su pagina cuanto es el costo enviar a peru espesificamente Iquitos loreto peru

Hola Loreto,
Para obtener más información puede visitar y el costo para enviar a Perú es USD158.00

Saludos cordiales,
Jestine Yong


Hi Jestine,

In that case If I purchase your ebook on “LCD Monitor Repair’, will it be helpful and applicable to me, cos I am mostly dealing with TV repair.
Please advice.

Thank you.

Hi Richard,
It has some tips that can help out in tv repair too because all these equipment involved electronic components. In my company, i’m starting getting more and more lcd monitors and the trend already started where the crt monitor is getting lesser in the market. Get this ebook to prepare yourself first. Have a good day!


hi jestin

There is one more question how i can know volt of this diode hz16-3l can you tell me.that will be great.
thank you have a great day

Hi Ismael,
Your answer can be found here:


Hi Kevin Cox,

Here are your questions and answers:

Thanks so much for the email, it was interesting to read your life story in Electronics, mine has been a similar path, while at school in the fifties I use to make crystal set and was keen on a future in Electronics but I was just a couple of months too young to join classes in being a technician in training with the local telecom. This has bugged me all of my life as I have missed my forte I think. I am semi retired now but still love Electronics , I completed a correspondence course in tv and video repair but as you mentioned it’s all theory and very little hands on , this has frustrated me a lot , I also became an amatuer radio operator which required having to pass test on Electronic Theory. Without someone to guide you it is very difficult to get a lot of experience until I read your ebook which was a shock to me having someone in the Industry giving away tips. Most Technicians don’t want to help you as they think you are stealing there work.

Nice to hear about your background in electronics and yes I’ve known lots of repair technician that is not willing to share out their secrets causing me have a hard time to learn from my own. I have spent countless hours to visit forum, read lots of repair books and do my own R and D in components. This result was my hardwork and never come easy to me.

I have worked in the computer industry for many years , building and repairing most thing except monitors untill recently and with the growth of flat screen monitor things could get busy. I read your ebook on Lcd monitor repairs but there is too much to take in for now I will have to keep revising it and I may print it out to make it a bit easier to handle.I did learn a lot from my first read and the colour photo’s are a great help.

Thanks for your support on my ebooks and glad that you liked it.

I have a few projects here that I am having difficulty with , and LCD screen with Power but nothing on the screen , I found two transistors faulty in the high voltage section but cannot find a replacement for them eg ( C5707 ) I have looked in my suppliers book but without success I may try the net.

Try I have ordered from them before and their service was very good.

I also have a colour television with the blue gun not working , I have checked most of the parts on the little board on the back of the tube without success and swapped some transistors around , I did a voltage check and found that they all have -4volts at the base.

The best to check colour section is to use scope. A line can carry voltage and a signal. Perhaps in your case the signal (blue colour waveform) has gone missing and you need to trace it out.

I use a isolation transformer which I made along with a Dick Smith ESR meter which I also assembled.

DIY is still the best!

I feel that I don’t know quite enough or I lack the confidence to try new tests, I don’t have any friend that I could ask but your ebook has got me thinking a bit more on a new line of testing. I repaired my television that would not start (faulty cap) and some bad solder joints plus a few other TV’s with loosing colours and shrinking screens these were mainly bad solder joints on the rear board or the TDA chip. Once you have done a job you learn so much with each success and then it comes back with the next similar job.

You are right, the more you repair the more you will gain!

The one piece of Equipment that I do not have is an Oscilloscope which I think is a must , I have many books on Electronics , digital multimeters and analog plus magnifying light, it’s not the equipment that is lacking mainly but know how.

I suggest that you get a used scope from EBAY DOT COM as this test equipment is a must in electronic repair.

Once again thank you for the email and a great ebook , I will purchase the other ebook shortly to improve my knowledge.

Thanks again for your support!

Have a good day!

best regards,
Jestine Yong


Dear Sir,

I need help to repair my ATX P4 450 watt PSU for my pc. I need ebook for that if you have or can make it for me. My PSU problem is :

– My Lan network no detect but if I change with new PSU my computer work well.

As you know PSU have rail 12 volt – 5 volt – 3 volt

But sometime volt for that all rails is down.

Les then 12 volt – 5 volt – 3 volt

What I can do to repair rail volt not down ?

Best regards


Hi Danny,
First i would like to say thanks for your support on my ebook. At current moment i’m still writing my fourth in SMPS repair but first you need to study this guide testing electronic components before you can go any further. In your case it could be electrolytic capacitor problem. Try open up the power supply (with power off) and check if there is any electrolytic capacitors bulged and if you have the Blue ESR meter then it would be great to locate such a fault. If possible take few photos of the internal power supply and show me and hope to easily guide you from there. If you have other questions please do email me again.



downloaded the LCD monitor repair manual and repaired my first benq by changing the pico fuse now on to the next one and try and find out whets wrong with a FSPO43 power board

Many Thanks


Hi wayne,
Thanks for the support and good to hear about your success story!


Dear Jestine

Thanks for your newsletter for October. Could you please help us – we are looking for the service modes of all TVs. At the moment we are looking a Logik 74 cm TV model no: RC-QO4M-OA.

Your assistance is this matter will be much appreciated.

Thanks & regards


Hi Eve,
Sorry i do not have service mode info for TV. Have you try ?


Good morning sir..

I would like to get your advice regarding my problem on power supply.

The power supply card input is 24VDc and output is 24VDC, +/- 15VDc.

My problem is when the power supply is switch on 1st time it work accordingly. After switch off and on again it is not work.

After a long time in off state and switch on again it work accordingly.

Could you advice my problem sir?

Hi Anuar,
it could be a start up resistor problem in the primary circuit. I do come across similar problem and the solution is to replace the power IC.


Dear sir,

I have 21 inch Dell Trinitron monitor Flat screen. model number is Ultra scan P1110 Ser no, 2 3 4 4 3 5 9 Maid in Japan. i have problem when i on the monitor he showing R.G.B cable signal . then i connect the cable with C.P.U the disply is on but within 1 mints the disply gone. and monitor L.E.D Belinking . ( like continue on /off / ) can u tell me wht fault in this monitor . i am waiting ur reply . As soon As possible.

Hi Atif,
You have to open up the monitor and test out the out put voltage to see if it too high or not. Check all the e-caps too. If you have the high voltage probe you could know if it shutdown was cause by a too high voltage or not. Is the display perfectly good before it shutdown?


Hi Alex,

Here are your questions and answers:

First please note that I have mistakenly posted this question in the privacy policy section. I am sorry for that. Hope it isn’t too much trouble to remove it.

No problem!

I am a computer engineering student. I decided to try fix and sell monitors.

I purchased your LCD monitor e-book a while ago and have since then have been able to repair a few monitors. Mostly they were capacitor replacements. One had a couple of shorted transistors.

Thanks for the support!

I have a LCD monitor that is a tough one to fix. It is a MAG 19″ LT916s Model no: 900p. The problem is that it has display shutdown problem. It initially worked when the brightness was turned down low. I thought that the mosfets that drive the inverter were bad, so I changed them. That did not solve the problem; it seemed only to make it worse. The shutdown is now faster and not operating even on a low brightness setting. The problem could have been made worse by me by trying to check whether the two mosfets in question were running hot. When I touched them the D444 mosfets, they were not hot, but the monitor shutdown.

A bad backlight could such problem (intermittent or permanent) that you have described. have you try to substitute with another backlight?

The capacitors look good in the monitor. I now suspect that the problem might be with the transformers. One of the transformers makes a humming noise when a 5V ~100Hz squarewave signal is applied to it. I am not completely sure if that is a problem, but I do not think so. The other transformer’s signal output has an unstable output. What I mean by unstable is that there are several waveforms on the oscilloscope screen versus one steady waveform on the secondary side when a signal is applied to the primary section.

I’m not sure about that but what i’m sure is if you want to test a high voltage transformer that runs on 50 to 100 khz, you should get at least a 16 or 32 khz test signal to apply to the transformer instead of only 100hz. 100 Hz would be not enough to accurately test the transformer.

I have been using a crude function generator, scope, capacitor method to act as a flyback tester. Both the transformers have an almost identical ring to them on their primary and secondary sides.

This method works too and the function just like the flyback tester. If both rings good then try suspect the lamp

I think that one of the transformers might be bad. I would like to try the burnt transformer technique solution. I understand that you have to have the feedback signals connected so that the monitor will not immediately shutdown when one channel is not connected to the lamps. However can I leave the bad transformer in the circuit without cutting any traces or must I disconnect it?

You can just temporarily disable the secondary pin of the transformer. If the circuit works okay after the modification then i suggest that you remove the whole transformer or cut off the circuit.

Also can I simply disconnect the feedback pin of the inverter IC and leave that channel not hooked up? Will that work?

I have try some model of inverter ic could work while some will immediately shutdown if without the feedback signal.

Finally I decided to buy an analog multimeter since some components are best tested by it. However on I read a post where you said that analog multimeters that do not have an internal 9V battery don’t test mosfets well. I bought the same analog multimeter that you are using in the LCD monitor book the Sunwa YX-360TRN. However it seems (It hasn’t arrived yet) that it runs off of two 1.5V batteries.

The analog meter should have the 9 VOLT AND THE 2 X 1.5 VOLTS batteries in it. However if the meter have the X10k ohm range it should have the 9 volt battery inside. Just don’t get the X100k ANALOG METER.

Best regards,

Jestine Yong


Hi Andi,

About the zener diode tester,the transformer output 12v 0 12V so where to connect the 0 that is the center tap, I had made one but not functioning.

Leave the 0 volt alone.

Can I use a 15VDC output for that purpose?

15 volt will produce a lower voltage compare to 24 volt.

For your info I use a 2 amp bridge rectifter instead of using IN 4007 diode does that cause the problem.

No, in fact you can use the 1n4002 diode.

For the acer flyback I’ll send it to you in a few days time and I need your address.


Can I use a 14″ acer monitor flyback to 15″ monitor.

If the pinout configuration is the same, yes you can try to use one.

Hi Jestine :

Again, thank you very much for this new repair newsletter,I appriciate this very much,even though I am not in the consumer electronics servicing but I’ve learned from it and I gather more information in testing electronic component and more ideas in troubleshooting.

Thanks & regards,


Hi Richard,

Here are your questions and answers:

Today I started to use your Blue ESR Meter. I have some doubts wish to clarify from you.

(A) Non Polarized Capacitors

(i) The following caps does not show any reading. Does it mean all of them are bad?

822J / 1.6KV

123H / 1250V

.012M / 250

No, because ESR meter can’t test the non polar cap with value less than 0.1uf

(ii) Can the meter test non-pol cap below 0.1uf?

No it can’t

(B) Electrolytic Capacitors

In the following e-caps, its ESR Ohms reading are:-

1uf / 250V = 7.2 ESR ohms

1 uf / 350V = 9.2 ESR ohms

0.46 uf / 50V = 14 ESR ohms

(i) Is it all good?

Yes the esr value is good. Is there a cap with 0.46uf? I though is 0.47uf

I saw your previous Dick Smith ESR Meter has figures-type label on its casing whereas the Blue ESR Meter only has graph-type label on its casing.M ay I have a photostate copy of the figures-type label of your previous Dick Smith ESR Meter ?

Try this link

I used to come across BP Cap in TV. Is BP stands for Bi-polarized?


What are the different between these 2 type of caps?

Can a BP cap be replaced with a Polarized cap?

Please visit the link below



By the way, your site in internet is really remarkable. Just for the record, I have been involved in the repair business for many years in the past, as a service technician in the representatives of Panasonic and JVC in Greece sequentially (almost for seven years in total). After that, a more than 15 years period followed with my involvement in the industry, having the tasks of installing and repairing telecom equipment. Now I have office tasks, but the “virus” is still alive!

Ha ha you are right the virus is still alive. I got this virus since i was very young! Nice to know about your background too!

I wish I had tools like that at that time…The years of troubleshooting based on “primitive” electronics methodologies….Especially during the early years, before the privilege of experience had come…

Without the right tools it will take a longer time for us to find out the fault. I don’t like to guess thus i invested heavily in the test equipment.

Have a good day!

Best regards,

Jestine Yong


Hi A,

Here are your questions and answers:

Hi mr. yong to cut short this long story you are Guru of this electronics stuff I have been benifit for long time now with you are short notes and news letter which is real real good for hobbisity folks thankx God.

You are welcome!

Now Got a problem with one monitor old version AOC colour monitor model: 4vrl,FCC ID ARSCM 3500
the fault is c=710 is blown out and R=733,R=734,R369 all of them are burnt you can’t even read the value? and what could be the fault and waht their value also now i can focus what you have been said before there a lot of opportunity if you get right info i’m still collecting the money and i have you are bank account number i will send soon don’t bother about me

If too many components you have to depends on schematic to find out the value. have you try ?

i have Fujitsu Plasma error code 3

For your information my ebook does not cover Plasma tv repair

and ve got dell LCD monitor all need your skill plus u’r books to sort out this issues im sure i’ll buy them course i miss a lot of money !!!!!!!!!!!!!ok please help me those value of my monitor and God may bless you ahmeh.

Thanks for your support again
Hi Samadhan,

Here are your questions and answers:

Thanks For the you send to me very important repair information .
this month i repair the industrial monochrome monitor.

Good to hear that!

currently we start repairing of 46” LCD but this LCD focus problem.
i switch on the power that time we can not see the OSD Display.
we not see the clear this massage (Check The Video Cable)
i think Focus problem but problem is not solve
you pl adv Me. Awaiting your valuable reply.

Could it be the backlight is not working and the display is very blur? Could you take a picture to show me-thanks!


Hi Aaron,

Here are your questions and answers:

i have been reading your news letter and learn quite a bit

Thanks for the support!

but iam having problem with tv’s repair iam working on to tv’s i have check every thing on the boards and they seems to be good unless i am missing something else,each tv problem is not coming on at all i can here a click when i plug them up and thats it. but on the rca tv a stand by light comes on when i plug it up and that is all when i push the power button nothing happen and on the zenth nothing happens just a click on the board please give me some input on this problem or what i might be doing wrong,

If the standby circuit is working then make sure the signal send out from the cpu/microprocessor is reaching to a relay circuit or to optoisolator. Once the relay is triggered the ac will flow to the main power supply and you will get all the output voltages thus your tv will work. If the main power supply itself have problem, there will no output voltages. Check if the power IC in the mainboard is receiving supply or not. Hope this helps!

and were is the best place to purches a tv schamatic

Try free website

Hi Jestine,

Yes, I have read your report. It’s very informative. Thank you.

By the way, I would like to know from you, how do you solder and dis-solder the surface mount ICs or digital Transistors.

Do you have any special tools for it? I found that with the ordinary soldering gun an dis-soldering gun(sucker) , are very hard to do the work. Especially this type of surface mount IC, their pins are so tinny and so close to each other.

Please advice.

Thank you.

Hi R,
The best is to invest in a rework station. Nowadays rework station are selling very cheap.


Hola amigos
veo muy interesante vuestra web, pero el problema que no sabr?a escribirles
en ingles as? que si queréis Vds. me escrib?s en ingles y yo en espa?ol,
gracias y un saludo

Hola amigo,
Gracias por tu interés en mi sitio web, pero sólo lo siento i entender Inglés, y no español. Que tengas un buen día!

Saludos cordiales,


Hi Jestine,

In your report on “How To Repair BENQ FP731 17″ LCD Monitor With No Power System”, you mentioned in your last paragraph on page 3, “…………….but of course the SMPS primary winding you have to use a flyback tester to test it”. My question is if we use the Blue Ring Tester instead of the Flyback Tester, can the Blue Ring Tester test it out as well?

Thank you

Hi Richard,

Yes definitely the BLue Ring Tester can test it. In fact it was designed to test SMPS and other coils as well. Please visit



Here are your questions and answers:

What is a ‘Rework Station’ that you mentioned? Can you elaborate on this? How much will it cost?

It is about USD90 depending on model and all are made in China. Here is the link of photo

I think you would laugh on me that I never come across it. Is a shame to tell you that we, staying in a small town, everything that is new won’t come to us that fast. It’s quite lucky that nowadays with the help of Internet we can learn a lots from friends out there. Otherwise we are just like a frog in the well. And it’s is lucky that I came to know you. Do you think so? hi…hi…

No i won’t laugh at you because i’ve been in your position before. Just keep working hard, invest in the test equipment and related information, never give up and i’m sure you will be good in the shortest time compare to my time where no one teach me!


Dear Mr. Yong,

Good day to you! I am an electronic enthusiasts. I have a question in relation to electronics. This is regarding my television set. When I turn it on, at first it will work normally until the screen will appear like a line across the screen in horizontal position. The sound and images are still working properly. What’s wrong with my television? What component do I have to locate and replace? Hope you can shed some lights regarding this matter. Thank you so much and more power to you. Hope to hear from you the soonest.

Best regards,

Jomar L

Hi Jomar,

Try check for dry joints especially in the vertical output IC area. Sometimes bad e-caps in the power section that supply the voltage to vertical section could have problem too. Hope this helps!

Do you know where I can get inverter high voltage transformers? Having a
hard time finding them on the internet.


Out of a Optiquest Q7 17″ LCD.

In your book you say to test the phototransistor you have to put the meter on the base, emitter and collector. There are only 4 pins on the optocoupler. Isnt the base internal ? How do I put my meter on the base? There is only the emitter and collector pins coming out of the IC, pins 3 an 4. Pins 1 and 2 are the LED / Diode.


Hi Danny,
Try email this supplier at and look for luca to check if he has the parts you are looking for.

Some optoisolator IC does not have the base and you just test on the collector and the emitter the same way you test on bipolar transistor collector and emitter. Hope this helps!







  1. Dave Gray

    January 10, 2009 at 9:43 pm

    Could you perhaps have contact details for spares regarding Philips GFL7D projection T v system in South Africa



  2. admin

    January 13, 2009 at 10:47 pm

    Hi Dave,
    Sorry no contact in South Africa.


  3. Mihir

    October 10, 2009 at 1:40 pm

    hi Justine i am mihir Patel from India i want learn that what is high voltage in electronic circuits so please send answere

  4. admin

    October 10, 2009 at 4:02 pm

    Hi Mihir,

    Try this link:



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