Don't Miss

Electronics Repair Questions/Answers and Testimonials -Part 70

By Jestine Yong on December 27, 2010

Hi Jestine,

first of all, thank you for your monthly letters and email support for the whole year. i remember i bought your ebooks in march of this year and i began to study electronics by reading your ebooks as a beginner.. now, honestly, besides fixing computers, i fix a lot of monitors and tv in my computer store and make a lot of money from them. your ebooks and email supports help me a lot in my business, at the end of this year, i would like to say thank to you and happy new year. god bless a good person like you and your whole family.

ming

=========================

thank you i got my power supply working using your book and other articles , it saved us 2700 dollars getting this machine working again.

Bob

=======================

Hi Jestine

Many thanks for your kind help and support on this ic I could not locate anywere in England UK.

When I emailed you a few days back asking if you could suply me with this ic, you very kindly sent me a link on were to buy some from (Utsource) I emailed them asking if they can sell me 2 of these and they said yes $2 each.

Jestine I had been trying for over 1 year to get this ic and not available in UK, I tried some other sites and they had them BUT minimum order was 500 pieces, well I only needed 2 so I couldn’t afford to buy 500.

I am going to send for some after Christmas, cost will be $13 with postage.

Jestine when I looked at the Pacific dvd player with no power I was repairing, I checked all caps diodes resistors etc and all were OK, I then start to follow your method looking for bulging caps and then I look at this ic and I saw from my eyes that pins 1 and 2 had burn marks on them, I had a spare dvd the same has this so I took ic out and put it in faulty one and it Powered up and working fine.

Many Many thanks for your support and help Jestine, I hope you and your family have a great Christmas.

Kindest Regards from Alan (England UK)

==================================

Hi Jestine

Firstly may I thank you for the superb service I have received from you, I am really very grateful. I would also like to thank you for the two bonus books as well, from which I will be building both the zener and pwm testers.

This is the 3rd book I have bought from you and once again this has helped me no end with various repairs I have carried out. As usual the smps book has been written with a clarity that that is extremely easy to follow and is something I have not as yet found anywhere else that even comes close to your books.

I will in the new year be buying the burnt resistor book from you.

Once again many thanks for your help and may I take this opportunity to wish both you and your family a happy christmas and a great new year.

Once again many thanks

Philip

===============================

Hi Sir,

I have a problem studying SMD Capacitor, Can you please help me. in your LCD Book in page 85 their are photos of TYPICAL SMD CAPACITORS and in page 89 and 90 you check it using the Digital Capacitance Meter and Smart Tweezers. My problem is how to know the capacitance value of a typical SMD capacitor, because I can’t see any coded letter of number in the body of typical SMD Capacitor, that’s why I cant select the proper capacitance range in digital capacitance meter. even though I got a value I still dont know if this is the right capacitance value of that SMD capacitor. And are these non polar capacitor? Please help me..

Thank you and God Bless
Jerry

Hi Jerry,

Thanks for your email. This is one of the problem face by repair tech because manufacturers do not provide enough information about the color coding. Since a motherboard have more than one smd capacitor with the same color thus their capacitance value must be the same. This SMD cap value is usually small. If you measure a small red smd cap and you got 1nf then the other small red smd cap should have 1nf too. Yes thos smd cap are non polar caps.

Jestine

============================

Hi Jestine,

Hope you are doing fine. I have question with the power supply of LCD monitor/tv. The monitor does not display while the power light is green. I checked the power supply connecting the main/logic board and only a few parts of filters receive low voltages. I disconnected the mainboard and checked the power supply alone. It shows only 5 volts at one pin. Other pins that should supply 12 V and 5 V do not show any voltage present. Could this be the power supply faulty or the main board that would draw the 12 V supplies etc.?

Rikhuma

HI Rik,

Many lcd power supply could work even without the mainboard but to some it can only produce 12 volt when the mainboard send an on signal to the optoisolator ic to trigger the primary side in order to produce 12 volt. I suggest that you check all components along the 12 volt supply line. It can be filter cap or even an open secondary diode.

Jestine

===========================

Dear Jestin,

My name is Alan and I live in England UK.

I have your ebooks on repairing files and it is brilliant, I have learned so much from you, I am 18 years old and have found your help to be brilliant, you are a really great clever guy.

===========================

Hi Jestine,

This is a LG 505G CRT monitor. The first problem was it couldn’t be switched on because the 1000uF 10V for the 5V line had a high ESR value. After replacing it, now it works normal accept that the display has a light brighter long shadow to its right; the focus is OK because any character can be seen clearly. It’s a pity that my camera cannot take this photo of this problem clearly, almost hardly seen.

What part/ component could be causing this problem, do you think?

Thanks again

Bailing

Hi Bailing,

Make sure the heater have 6.3 volt. If the voltage is lower or the tube is weak then it could cause shadow.

Jestine

===================================

Hi, Jestine
Thanks I have received your letter. It was very good book and I get alot of advancement I treated you as also my guru,you are not also teach technical but also about life.
Sincerelly,
zaki

=============================

HI NG,

Thank you so much for helps.

You are welcome!

I had questions in regard to SUNWA Analog meter. Inside the meter, there are two battery compartment, one for 2 X 1.5 V AA battery and another is for 9V battery. It worked on the 2X AA but when I taken out the AA batteries and placed a 9V battery, the meter does not respond. I bought this meter because it was used in the ebook and my friend also told me it was a very good meter both in quality and value. I think it is great as I now love this meter so much after learning from ebook.

Can you put both 3v and 9 V simultaneously?

Yes you need to put all in order for the meter to fully function.

Why there are two battery compartment?

3 volt is for the x1 ohm, x10ohm and x1 k ohm range. 9v is for x 10 k ohm range.

My Sunwa meter was model was ending with e and your is slightly difference, do you have any idea what is the major difference? I read the manual but it do not understood.

Actually there are lots of different types of Sunwa meter in the market. One copy another. The most important is that it must have the 10 k ohm range in order to accurately test diode, zener diode, transistor and fet

Jestine

=================================

Jestine:

I have been reading your newsletter and I’m thinking in buying your SMPS book but before I do that I want to have some equipments so I have what I need to test components. Also my money is tied and I’m trying to buy what I need as cheap as possible. Anyways, I was looking on the internet and I found this Heathkit yoke / Flyback tester IT-5235 (picture attached) and I was wondering if that one will be good for testing transformers or is it too old already.

Thank you very much for your response,

Sincerely,

Ianbel

Hi Ianbel,

Thanks for your email. Since i have not use this tester before thus i can’t give any comment about it. However, this tester is designed to test coil thus i believe it can be used to test on switch more transformer and other type of coils. If the price is cheap you can get one and try it out.

Jestine

=============================

Hi Jestine,

Yes, your answer is just right. The battery liquid is still there though we cannot see it, even I had cleaned it a few times. Every week if I reopen to see the board, the little liquid vapour is still on the brown side ( no solder part ) of the pcb causing a few buttons cannot work. Maybe I should reclean it several times.

The reason I insist to repair it is because there is no exact remote controller in the market.

Thank you very much,

Bailing

==============================

Dear MR. Jestine

one by one kabel backlight pada board sudah saya remove dan masih seperti semula. board ini menggunakan IC inverter OZ9938 dan IC mosfet AP9971M. kemudian saya cek tegangan drive (DRV 1 dan DRV 2)pada pin 1 dan 15 pada IC OZ9938, ada tegangan sebentar kemudian hilang. ada petunjuk lainnya my guru?

thanks

edi

Hi Edi,

You have to replace one backlight at a time to test it out. You can’t remove the backlight cable one by one because this can cause shutdown. You need a good baclklight in order to confirm it. There are feedback circuit in lcd and it if you remove the cable the display will shutdown.

Jestine

===============================

HI Hussien,

Thank so much for your response and I would like to tell you my targeted customer is every house in Riyadh where every body here has TV ,dvd player, video game , telephone , digital camera and computer.
What resources are required? equipments , devices …etc

The business field that you are targeting is too wide and i can’t provide all the details because different repair field may need different type of test equipment or even tools. However the common test equipment for many repair jobs are:

analog/digital meter
digital capacitance meter
Blue ESR meter
Blue Ring Tester and

Oscilloscope.

Do this center need electronics engineer or technecians?

Yes definitely because without them the repair job cannot be done.

local manpower is not available from where I can hire comptent people from India ,China or philippines?

This you may need to check from your Government of which country people you can source. Good techinians can be from any of the country you have mentioned.

Jestine
http://www.JestineYong.com

==================================

HI Noorishkandar,

Hello Encik Jestine, saya tengah membaiki sebuah TV LCD brand Philips 32″
Customer beritahu tiada power,apabila saya buka cover dia saya dapati Fius
dibahagian power supply dah blow so saya troubleshoot seperti biasa dengan
menguji setiap komponen seperti diode dan juga transistor.

Apabila saya dapati komponen ini dalam keadaan baik saya terus replace satu
Fius baru tapi apabila saya switch on power Fius yang baru diganti ini blow semula.
Pada pendapat Encik Jestine apakah lagi masalah yang boleh menyebabkab Fius
blow?Disini saya ada attachkan gambar bahagian power board tersebut.Saya berharap sangat Encik Jestine dapat membantu saya dalam masalah ini dengan memberikan pendapat serta tips-tips cara nak mengatasi masalah ini.Akhirkata saya
ucapkan ribuan terima kasih.

Kamu kena check semua semiconductor. Biasanya semiconductor yg menyebabkan fuse terbakar. Kalau boleh terus tukar power ic dan retest.

jestine

===================================

Dear Mr. Yong

Sorry, It is not FBT it is High Voltage Transformer. Please let me know why its giving high noise near power circuit. What to check.

Thank You.

HI Fakhruddin,

Usually there is component faulty that had cause the transformer to produce sound. Sometimes, a bad transformer or inductor may also cause high pitch sound.

Jestine

=======================================

Likes

(0)Dislikes

(0)

8 Comments

manu

December 27, 2010 at 8:13 am

sir,

what is the voltage rating of a ceramic capacitor?
In a ceramic capacitor only its value is written on them like 104,105etc.

Likes(0)Dislikes(0)

Reply
admin

December 28, 2010 at 11:18 am

HI Manu,

If there is no value printed on the body, then it should be about 100 volt. For the bigger size ceramic the value is 500 volt.

Jestine

Likes(0)Dislikes(0)

Reply
ehsan

January 22, 2011 at 3:27 pm

Dear Mr. Yong
i have Problem at lcd broken..there are no Same components but
i found a Different one
now i ask you as Friend for connect that lcd screen with a Different type

Likes(0)Dislikes(0)

Reply
admin

January 24, 2011 at 9:51 am

HI Ehsan,

If the connector is the same then you can try it out.

Jestine

Likes(0)Dislikes(0)

Reply
ehsan

January 24, 2011 at 1:40 pm

Hi Jestine,
I just need the datasheet for these two ics
NEC BU25507-02 AND EPSON TCON-8.9-F

Thank you very much,
EHSAN

Likes(0)Dislikes(0)

Reply
admin

January 24, 2011 at 7:59 pm

HI Ehsan,

Sorry i could not get the ic datasheet. Info for printer IC's is usually hard to get from the internet.

Jestine

Likes(0)Dislikes(0)

Reply
ehsan

January 24, 2011 at 11:47 pm

sir
thank you for your answer
but the IC what i need its datasheet are not printer components
the one is for the broken lcd screen (AS YOU SEEN IN THE PICTURE)
and second IC it is for lcd screen what i want to Linked

BEST REGARDS
Ehsan

Likes(0)Dislikes(0)

Reply
admin

January 26, 2011 at 6:23 am

HI Ehsan,

Sorry i do not have such info.

Jestine

Likes(0)Dislikes(0)

Reply