Backlight failed on approx 7 yr old Samsung TV

Forums › Home Theatre (including HTPC and EPG Collector) › Backlight failed on approx 7 yr old Samsung TV - easy fix or bin it??

Blurtie

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Ultimate Geek
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#275912 16-Sep-2020 15:24

Hey all,

As per subject, the back light failed a year or two ago and has been sitting in the shed gathering dust.. I'm assuming it's the back light as I still get sound from the TV.

Just wondering if it's a cheap/easy fix? I've seen a couple of youtube videos which looks pretty intensive, but would be interested to hear whether others have tried and successfully fixed this issue?

vexxxboy

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#2566038 16-Sep-2020 15:27

personally if it was brand new and it went a couple of years ago i would have been claiming under the CGA, but you may have missed that option.

Common sense is not as common as you think.

wellygary

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#2566046 16-Sep-2020 15:37

If you know what the actual fault is (e.g actual physical fault in the LEDs) then it might be worth seeing if you can source a replacement part (Alix /wherever)..

BUT it could just as equally be the power supply, or the controller, or the whtever.....

Unless you have experience at trouble shooting electronics or plenty of time on your hand it might simply be worth binning it...

elpenguino

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#2566052 16-Sep-2020 15:46

Keep your eye out for a second hand unit , ideally that's got screen /drop damage and have a go at making one out of two.

Most of the posters in this thread are just like chimpanzees on MDMA, full of feelings of bonhomie, joy, and optimism. Fred99 8/4/21

Blurtie

487 posts

Ultimate Geek
+1 received by user: 131

#2566053 16-Sep-2020 15:49

Yeah to be honest it wasn't a very expensive TV, so when it failed I wasn't overly bothered by it failing, was more upset that I couldn't watch TV!

As it's gathering dust in the shed, I don't really have much to lose, so I'm prepared to spend some time on it and have a play around. A quick google search for back lights seems relatively inexpensive, so if it can be repaired by just replacing that part then that would be pretty sweet.

Zeon

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#2566068 16-Sep-2020 16:15

If you need to replace the actual backlights it is a very tricky job in my experience and easy to get the screen to get dust in it and warped. If it's LED each LED shouldn't fail at once so hopefully its the power supply...

Speedtest 2019-10-14

Blurtie

487 posts

Ultimate Geek
+1 received by user: 131

#2566076 16-Sep-2020 16:29

Zeon:

If you need to replace the actual backlights it is a very tricky job in my experience and easy to get the screen to get dust in it and warped. If it's LED each LED shouldn't fail at once so hopefully its the power supply...

Thanks Zeon, good to know! So how would I go about testing it to concretely confirm if it's the back light or the power supply?

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GGJohnstone

86 posts

Master Geek
+1 received by user: 5

#2566404 17-Sep-2020 07:34

Aliexpress sourced

UA32D4003B power board

working but delivery took months. This was a direct replacement by part number. There was no voltage on the failed one after the heat sunk I.C. after replacing a small burnt capacitor and an on board fuse so the replacement at worst might have provided the I.C.

Not an economic repair by any measure.

Zeon

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#2566611 17-Sep-2020 09:28

Blurtie:

Zeon:

If you need to replace the actual backlights it is a very tricky job in my experience and easy to get the screen to get dust in it and warped. If it's LED each LED shouldn't fail at once so hopefully its the power supply...

Thanks Zeon, good to know! So how would I go about testing it to concretely confirm if it's the back light or the power supply?

The easiest way would be to take the back cover off so the power supply is exposed. In my experience of computer monitors is that there are usually 2x cables going from one side of the power supply to each of the backlights. If you turn the screen on, with a voltmeter check if there is voltage on the plugs. Be quite careful though as parts of that PSU will have at least 240v AC power going through them. If its CCFL, there could be much greater voltage too.

Looking at the board link from Aliexpress above its not clear where those cables plug in. You may need to track them.

Speedtest 2019-10-14

Blurtie

487 posts

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#2566697 17-Sep-2020 10:48

Thanks all, will try and test the power board and cross my fingers that that's the fault.. Looking at the prices from Aliex for a power board seems reasonable enough and something I'd be prepared to pay to try and get some extra life out of this TV. Hate to bin something like this if it's just a relatively simple fix.

It will only be used as a spare - probably in the kids room; so no big drama if it doesn't work.

GGJohnstone

86 posts

Master Geek
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#2566714 17-Sep-2020 10:58

That looks like my board. The cap down from the I.C was blacked and the fuse further down the board was open cct.

It would be fair to think that the design would be engineered to age gracefully with wide Qs and negative feed back so a total stop might be due to one thing. The replacement appeared to have been in use much longer than my original but it is working so I hope that the replacement has replaced that one thing.