Vertical trouble in Monitor AOC Model CT500n repaired
The electronic appliance that we will see on this article is an AOC Color Monitor for Personal Computer Model CT500n.
This monitor AOC was having a serious trouble with the Vertical Deflection Circuit, as shown in photos below:
As we can see, it is impossible to have a Monitor with that kind of trouble in front of us; therefore the first step was to remove the cover and look for the defect in this electronic equipment. Here some photos shown:
The main trouble was localized to IC 601 (TDA4866A) area. It is a Full Bridge Current Driven Vertical Deflection Booster IC (from PHILIPS Semiconductors). There were many cold solder joints in the vertical IC legs as seen from the below photo.
There was also dust accumulated in some areas of the PCB Board, as shown below:
You can see the top and front view of the vertical output IC in the following photos:
The cold solder joints of the Vertical Deflection IC and surrounding area were soldered. The accumulated dust on the PCB Board was cleaned with a brush. Now the monitor is working like new as seen from the below photos.
This article was prepared for you by Mr Humberto Rodriguez from Cuba. Please give a support by clicking on the social buttons below. Your feedback on the post is welcome. Please leave it in the comments.
By the way if you have any good repair article that you want me to publish in this blog please do contact me HERE.
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Andy
September 29, 2013 at 12:00 am
It is amazing how many repairs involve cold solder joints or bad capacitors, and I wonder how many cold solder joints are a consequence of the new lead free solders; I always reflow with old fashioned lead solder.
I am very much for keeping old equipment running in good condition, but sometimes I wonder how much I waste in electricity, given that new units are often more efficient.
Robert Calk
September 29, 2013 at 10:14 am
I agree. Also since I have a bad back, I don't like them because they are too heavy.
Humberto
September 30, 2013 at 7:36 pm
Sorry Andy, I will correct my opinion: you are maybe rigt Andy, but in my own opinion the new units are much less durable than old units (taking into consideration some disadvatages of old units). Have a good day and thanks for your opinion.
Gerald Musy
September 30, 2013 at 3:31 pm
Hello Andy,
You are raising an excellent point about lead free solder. I am asking the question myself.
Recently I had to conduct trainings on electronic soldering for a European company. In Europe the solder containing lead is now forbidden so I had to use the lead free version. I tested various brands and compositions until I found one that allowed us to do solders that, at least, look good. But I don’t know about the long term reliability…
Like you, I still use the old fashion 60/40 solder for my repairs and projects. I think that lead free for manufacturing makes sense as there will be hundreds of thousands boards out there and it might have an impact on the environment.
But for the few solder joints we do during repair I prefer to choose the known reliability.
Cheers,
Gerald
Humberto
September 30, 2013 at 7:15 pm
You are maybe rigt Andy, but in my own opinion the new units are much less durable than new units (taking into consideration some disadvatages of old units). Have a good day and thanks for your opinion.
Robert
October 1, 2013 at 10:07 am
That's true that the screens are more easily damaged than the CRT's, but the picture quality is much better. I will never buy another CRT.
Robert
October 1, 2013 at 3:41 pm
Except for an oscilloscope...
Humberto
October 2, 2013 at 1:59 am
Sorry Robert, but you should find out with any Graphic Designer, because most of them in the whole world prefer CRT's than new technology in the graphic design, due to real color of them (taking into account their disaadvanteges: weight, damage for our eyes, and etc.)
Robert
October 2, 2013 at 3:19 pm
Oh please!!
mustabz
September 29, 2013 at 12:11 am
Well done jestine and thanks to Humberto for sharing its amazing how dust can mess up these gadgets. Just two days ago I had similar diagnostic issues. And just by blowing and s few resolder of a couple of joints two sets of Panasonic TVs came back to life.
Patience is the key.
Jestine Yong
September 29, 2013 at 8:30 am
Hi Mustabz,
You are welcome and thanks for sharing
Jestine
Kevin
September 29, 2013 at 12:37 am
Humberto, What great find. I have amazed at what small issues cause people to dispose of easily repaired but expensive to replace products. So many thing are tossed out because of a fuse, switch or cold solder joint. Keep up the good work!
Robert
September 29, 2013 at 5:48 pm
That's right, Kevin!! It's the fault of the repair shops not getting together and advertising!! At least that's the problem in the USA. They need to unite and share the cost for advertisement to let people know that the majority of problems with their TV's and Computers are usually low cost fixes.
It seems like the majority of people think it's cheaper to just buy a new one...
Humberto
October 2, 2013 at 2:09 am
That's right Robert, many times our electronic equipments may be repaired, and people preffer to tossed them out and do not realize that is very cheap to repair them in many cases.
Humberto
September 30, 2013 at 7:25 pm
Hi Kevin, take into consideration that my country's weather the humidity is very high, and this kind of trouble is very frequent. Best regards.
Gary Gemmell
September 29, 2013 at 12:55 am
Good fix - quick and easy - I Like.
When i worked for JVC manufacturing in East Kilbride the engineers always said the key to keeping your television up and running was to take the back off every 6 months and blow all the dust out with a gas canister , allow adequate ventilation if not increase it.
I have noticed with the new plasma televisions they do generate a massive amount of heat - sometimes i think miniaturisation is the key behind device failures especially laptops where too much heat builds up inside the case.
I have seen many Dell and Hp machines that overheat with dust buildup so much so that the Nvidia graphics chips separate from the motherboard due to the solder melting and the display collapses of course - reflow solder is the only fix!
Jestine Yong
September 29, 2013 at 8:36 am
HI Gary,
You are right. Not only plasma tv, LCD Monitor and LCD TV have the same fate too. dry joints, low quality components used plus heat means business for us.
Jestine
Humberto
October 2, 2013 at 1:21 am
You are completely right Gary Gemmell, every electronic appliance must be obtain a maintenance job every 6 months at least, but we should analice what kind of enviroment is surrounding us too, because I have clients who need maintenance to their PCs every 4 months. Thanks anyway for your opinion.
fathi
September 29, 2013 at 12:59 am
merci pour votre collaboration votre travail est interessant
Andre Gopee
September 29, 2013 at 1:13 am
Thanks for the article Mr. Humberto. Its good to know that these problems are not cause only by a damage component.
Andre
sora
September 29, 2013 at 3:01 am
thank you
Humberto
October 2, 2013 at 2:24 am
Thanks to you and Mr. Jestine Yong too, who gives me the opportunity to publicate my articles for showing everybody some tips to take them in mind for your future development, ok?
Dan
September 29, 2013 at 4:29 am
Yes, the IC was alright but cold solder joints were to blame, and the dust contributed. You lucked-out Thank you for sharing that.
raymundo.saura@yahoo.com
September 29, 2013 at 9:58 am
thanks for this article. I will help me a lot in my future repair if and when i will encounter this kind of repair.
thanks and GOD bless
Humberto
October 2, 2013 at 2:54 am
God not only bless me, He bless everybody who read these articles to learn much more everyday. Thanks to Mr. Jestine Yong for give us the opportunity of publicate everything we do.
Olusegun Fadare
September 29, 2013 at 10:06 am
Thanks for all the information, am realy gaining.
Robert Calk
September 29, 2013 at 10:13 am
Thanks for the article, Humberto.
milo
September 29, 2013 at 1:05 pm
Thanks a lot for this sharing of knowledge,it is truly helpful to us! kep sharing thanks......
Naseem
September 29, 2013 at 1:05 pm
thank you very much Mr Humberto for sharing such a good report with us. I would like you to share other monitor problems as well.
Regards,
gaudenio valdez
September 29, 2013 at 1:13 pm
thank you for this article it is very helpful for me.
Tesfaye kebede
September 29, 2013 at 2:52 pm
Thank you jestin
goutam deb
September 29, 2013 at 7:33 pm
thanks i know & repaired this faults
Idicula
September 29, 2013 at 9:21 pm
Thanks Jestine. Your reports are very good. I read all reports which you have send to me.
Edmond Balatayo
September 29, 2013 at 9:26 pm
simple but mostly people don;t know about this. thanks jestine and humberto for the helpful tips. God Bless.
peter djuh
September 29, 2013 at 9:38 pm
You are a wonderful mentor Mr Jestine, I'm progressing very well in my repairs due to repairs articles, thank u very much for being there for us
Jestine Yong
September 30, 2013 at 9:15 am
HI peter,
You are welcome!
Jestine
corriete
September 29, 2013 at 10:58 pm
wow. thanks good to see my Caribbean people getting involved.Mr Humberto great job. thank you to Jestine for doing such great work so we can all share.
Jestine Yong
September 30, 2013 at 9:15 am
Hi Corriete,
You are welcome!
Jestine
Leon Alliki
September 30, 2013 at 1:02 am
Thanks dear Jestine and thanks Mr. Humberto for your useful experience. I'll remember next time to clean the printed board.
Jestine Yong
September 30, 2013 at 9:18 am
Hi Leon,
Thanks for the support.
Jestine
ronald ruesta
September 30, 2013 at 1:10 am
very thank you jestine for you help all tech like me
Baddar
September 30, 2013 at 3:30 am
I don't know how can i thank you because of your emails and those important repair tips. Thank you very well mr Jestine.
Jestine Yong
September 30, 2013 at 9:13 am
Hi Baddar,
You are welcome!
Jestine
Espoir
September 30, 2013 at 3:43 am
i do like all your repair tips, they do help me. Thankyou for all information.
Poasi
September 30, 2013 at 5:47 am
Thank you Jestine for the great information received and also for Mr Humberto article. It does help me a lot with my preparation as planned to start a repair shop by beginning of next year
May God continue to bless you
Best Regards
Jestine Yong
September 30, 2013 at 9:18 am
Hi Poasi,
You are welcome!
Jestine
Marulitua Hutabarat
September 30, 2013 at 6:33 am
Hi Jestine,
thanks for your repair tips article.
I ask you a question : Did you ever repair the Eizo T566 monitor?
The trouble was no raster but only blinking green and yellow led.
Thanks in advance.
Cheers,
Marulitua Hutabarat
Jestine Yong
September 30, 2013 at 9:20 am
Hi Marulitua,
I have not repair that model before but I know Eizo have lots of bad and leaky e-caps. Is all the output voltages good and stable?
Jestine
wayne
September 30, 2013 at 10:59 am
good work Jestine.
Mark Tembo
September 30, 2013 at 10:30 pm
Hi Humberto,
These problems are quite common and I have also encoutered them on several ocassions. The only problem I have is when it comes to charging a customer. How much fee did you charge him/her ( equavalent dollar )? .
Jestine, dou have any standard charges on such repaired that you do not really replace any component, etc?
Regards, Mark.
Jestine Yong
October 1, 2013 at 9:17 am
Hi Mark,
My repair charge is standard. This means the charge is a flat rate regardless if components is replaced or not.
Jestine
Robert
October 1, 2013 at 10:14 am
Hello Mr. Yong. Do you mean that you just charge a flat rate according to the time that you've spent on the repair??
Jestine Yong
October 1, 2013 at 1:32 pm
Hi Robert,
Yes I will charge a flat rate regardles of the time involve. It is like give and takes. Simple problem or fee minutes job i still charge the same rate. A tough dog problem also charging the same rate. Usually there are more than 80% of simple problem as compare to hard to fix problem.
Jestine
Mark Tembo
October 1, 2013 at 5:25 pm
Thanks for opening me up. I now need to take a survey on how others charge generally. I think this is very important too.
Thanks,
Mark.
Bitrus (PROBITY)
October 1, 2013 at 1:59 am
Mr. Yong thanks so much to be sincere that i am benefiting enough. i still need more of your articles on electronic repair most especially computer/laptop repair.
edgar
October 1, 2013 at 2:38 pm
muy buena tus tips y todo tu pais saludos muchos saludos
zeeshan zamir
October 2, 2013 at 12:59 pm
Nice information thank you dear
Thomas
October 2, 2013 at 7:09 pm
Mr. Yong as I am still learning, I have noticed you follow the same logic I do when I troubleshoot. I can definetly appreciate that as well as the articles you have been sending. Do you have any articles on working with MOSfets or transistors? I am finding those to be confusing do to the vast variety of them. I don't just want to fix electronics, I want to be able to design my own circuits and to do so requires a firm understanding of how everything works.
Jestine Yong
October 3, 2013 at 10:56 am
HI Thomas,
Sorry I do not have those articles. I suggest that you try search for electronics design forum since you are keen on design your own circuits. You can also try purchase circuit design books from amazon.com to add more knowledge in this particular subject.
Jestine
Avik Sarkhel
October 2, 2013 at 8:46 pm
Sometimes simple problems becomes more difficult to find out.
Mehdi
October 4, 2013 at 12:09 pm
Hi Jestine
I'm happy and enjoy but I can't speak english well
so when ever does every body like visit I and my friends type this address and after register give me(digital84) private message for active account see you soon
Jestine Yong
October 4, 2013 at 8:58 pm
HI Mehdi,
Is ok coz I don't understand the website language.
Jestine
Mehdi
October 5, 2013 at 11:17 am
Hi jestine again
we try to add english language.
Mojy
October 5, 2013 at 1:49 am
Thanks for the article, Mr. Jestine Yong.
Nimal
October 5, 2013 at 4:42 pm
Thank you so much for your valuable repair info. I too prefer to use the CRT as it is reliable easy to get spares. Also now, I can count on you if I have a problem I cannot solve.
Gurpreet
October 26, 2013 at 3:56 pm
Hello Jestine
Thanks for sharing this electronic tip with me. Up to now i have just open monitor and just replace the cable with new one. I also afraid from it's high voltage tube current. But anyway nice job by Mr Humberto and you also for sharing this article with us.
Thanks
Gurpreet