MAP3202 LED Driver IC Failure In 42″ LED TV
A friend of mine who works in a hard ware store brought me this TV for repair. It belongs to his mother in law. According to this lady, the TV stopped working without any notice. She explained that there was no indication of life in it.
This is a Korean made TV and I guess it was worth the repair. As I powered the TV up while customer awaits, the stand by light came on flashing and then the TV panel flashed for second then I could see the logo come on display but there was no back light to see what on the panel.
I used a flash light to check the display. Sorry I was not able to take photos of that since the customer was with me up to the moment I decided to take it apart and see.
Usually with this kind of symptoms, the main fault would be the back light not coming on because there is a shorted LED light in one of the lights or the back light boost circuit is faulty.
Here is the power supply and the main focus would be on the back light connector. When I tested with the multi meter the voltages that were supposed to be there, there was none. That is a clear indication that the power supply is faulty or the back light caused the black light circuit to go bad simply there was short in the back LED lights.
I first tested the LED lights with a special LED tester that I bought online. That saved me a lot of time taking the panel off to find out that there is nothing wrong with the LED lights. The back LED lights were in good working conditions.
As I tested the back light boost circuit, there were voltages reaching the IC but nothing was coming out. My logic sense was to replace the IC and hope for the best. The IC that you see in the photo is the replaced new one. I had a lot of these in my shop and they are very easy to find. The part number is MAP 3202. Here are the specs:
Please click on the photo above to access to the IC’s datasheet.
This is the old faulty part that was found in the back light boost circuit. The moment I powered up the TV, I got this.
I let it run for sometimes and it passed the test. The lady came with her son in law to get the TV. They were so happy to see the TV alive again and she was very generous in giving. Mission accomplished.
This article was prepared for you by Waleed Rishmawi, one of our ‘Master Authors’ and currently working in the Bethlehem area of Palestine repairing electrical and electronic equipment.
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Note: You may check out previous post in the below link:
https://jestineyong.com/many-suspects-for-a-no-sound-in-cd-player-repaired-model-safa-cd-21/
http://www.electronicsrepairfaq.com/a-melted-relay-and-clicking-noise-on-a-power-board-repaired
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Parasuraman Subramanian
April 2, 2019 at 9:39 pm
Excellent! As usual, a very professional approach and solution!
Waleed Rishmawi
April 3, 2019 at 5:12 pm
Parasurman: thank you so much. have a blessed day
Albert van Bemmelen
April 2, 2019 at 9:49 pm
Interesting repair with easy fix and datasheet of culprit Map3202 Led driver circuit. It would make these backlight repairs very easy if there just wouldn't be so many different led driver circuits.
Waleed Rishmawi
April 3, 2019 at 5:21 pm
Albert: agree. you can go online and build one back light booster and use it on all LED TV if you can not locate the booster IC. very easy to build and use.
Paul
April 3, 2019 at 5:45 am
Please could you elaborate on the special LED tester which you have used for this repair?
Waleed Rishmawi
April 3, 2019 at 5:27 pm
Paul: yes, there is a tester either you can build or buy on the internet. you can find ones that works on batteries or an AC source. it is actually a LED light booster tester. you can use it to find LED light that is burnt out in a LED TV. check out the link
https://www.banggood.com/0-320V-Output-All-Size-LED-LCD-TV-Backlight-Tester-Meter-Tool-for-LED-TV-Repair-p-1260998.html?gmcCountry=IL¤cy=ILS&createTmp=1&utm_source=googleshopping&utm_medium=cpc_union&utm_content=2zou&utm_campaign=ssc-il-all-0301&ad_id=335394503641&gclid=Cj0KCQjws5HlBRDIARIsAOomqA1FFz9X9kl5vvu9YMEw3OcqVvEkfnCjZlhj6xqjFJpNJ_99BmaXD-saAjUiEALw_wcB&cur_warehouse=CN
Jackson Lor
April 4, 2019 at 12:15 pm
Good job master,
Another knowledge that I've learned from you,,
Keep up the good work,
Waleed Rishmawi
April 5, 2019 at 4:20 pm
Jackson: thank you sir. I am glad you liked the article and that you learned something from it. it is a big encouragement to know that. have a blessed day
Patrick Ribbsaeter
April 5, 2019 at 5:15 am
Which LED tester did he use for the first test? any link where to buy it?
Thanks
Waleed Rishmawi
April 5, 2019 at 4:22 pm
Patrick: you can google it and you will find many of them that does actually the same function.
Martin
April 6, 2019 at 4:36 am
Dear waleed, thats a very informative repair article, how can i DIY a backlight tester? An step up with cc cv?
How much is an average voltage & current every led strip bar is needed? 24-30 volts or more? ( i want to save cost and use laboratory psu if possible)
Thanks alot!
Waleed Rishmawi
April 6, 2019 at 2:10 pm
Martin: if you can google how to make a Back light tester you would find a lot of them out there but what I have is already a made ready product and not that expensive.
https://www.youtube.com/watch?v=XMz7kEMYlkQ
this is what I have. I bought it for 53 dollars but I think the price went down since. it works on 100-220 AC volts. the think that I like about it. it gives out voltages as needed for the LED to come on. I recommend that device which is much better than the home made ones.
Yogesh Panchal
April 6, 2019 at 3:38 pm
Perfect repair approach! waleed.
Justice
April 23, 2019 at 6:44 pm
I like all the specs on the back light boost circuit IC, very interesting article thank you Waleed.