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File: 20171013_042627.jpg (3.98 MB, 5312x2988)
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Hey /diy/,

I'm attempting to fix this TV. It's a Samsung 42" LN40B530. The picture shows up for a couple of seconds then cuts to black, and keeps repeating this. Any idea what this could be? I have the TV open now and all I see is a slightly burnt part. Anyone know what part this is? Pic related. All the caps look decent. Knowledge isn't that great with electronics. Thanks for any help.
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that's a transformer, or maybe a dual transformer, that generates about 1000Vac to power the CCFLs (fluorescent back-lites). it looks cooked coz either itself or the light it's powering is dead. not worth repairing, just throw it out.
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I dont know about tvs myself but i fix audio receivers. if its cuts to black it could be some sort of protection feature or something, but that means that something else is wrong. There could be a temperature fuse inside the transformer that went off, I wouldn't bother fixing that.
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>>1259572
if you dont get around to fixing it how would you feel about sending me your logic and main board?

i have a 40" that went kaput a while ago gathering dust
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I had a similar experience with a Samsung TV a few years ago and the problem was a few "burnt out" capacitors. YT'd my way through replacing them and the TV has been working great ever since. First and only time I've done anything like that - so it wasn't too hard.
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>>1259572
>All the caps look decent
uh-huh. did you take them out and test them? i'm not saying it's ALWAYS the caps, but it's ALWAYS THE CAPS. the small electrolytics right next to the heatsink will be boiled dry, low capacitance high ESR erry time.
if you're only fixing one TV it's not even worth buying an ESR meter or universal bridge, just replace all the electrolytic caps except the two big smoothing caps on the input.

ps. little bit of char on the transformer insulation is no biggie those motherfuckers run HOT
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>>1259572
Show us some more pictures.
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File: 20171013_124257.jpg (3.51 MB, 5312x2988)
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>>1259594
Well I ordered that transformer off eBay for a few dollars. Going to replace it before I throw it away.

>>1259635
I would but I need to get this working. Only other TV I have is a 13" CRT.

>>1259680
Ok I'm going to replace all the caps and see if that does anything.

Thanks guys.
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File: 20171013_124302.jpg (3.95 MB, 5312x2988)
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File: 20171013_124306.jpg (3.51 MB, 5312x2988)
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File: 20171013_124310.jpg (3.67 MB, 5312x2988)
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here's an experiment worth trying. locate the CCFL connector that's closest to that burnt-up transformer and disconnect it. it's usually looks like the pic, with one pink and one white wire. sometimes it's 2 of each. plug the TV back in and see if that step stopped the display from going full dark. (it should only light up half-way coz you're only powering half the lamps.) but if it stays on, it means one of the lamps you disabled (or its associated transformer) is taking too much current which is causing the controller chip to shut all the lamps off.
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>>1259712
>Well I ordered that transformer off eBay for a few dollars
Great job, but where did you order it from? Why specify that you didn't order it from eBay, just tell us where you got it.
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>>1259774
Unfortunately I order it from China. It's all I could find. www.ebay.com/itm/1PCS-Inverter-Transformer-QGAH02095-For-SAMSUNG-BN44-00264B-/263135909182?hash=item3d441f553e
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>>1259774
>Why specify that you didn't order it from eBay
Give it up kid. You aren't going to change the world and it only annoys a few here on /diy/ so it really isn't worth the effort you're putting into it.
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>>1259800
Is that even english?
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>>1259849
>Is that even english?
No. It's English. Specifically, American English.
suck my dick - I know you faggots all understand that.
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>>1259800
Sounds like American. Its like english but more direct and without the fluff and bullshit.
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>>1259572
I have fixed several tv's buying the power board on eBay and just swapping it. usually $60
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>>1260688
Same here. Just shove the TV make and model into ebay with something like DRIVER BOARD or POWER BOARD and boom, fucking loads of em.

Also check for blown caps.
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Does it turn off, power light flicker, act like it was just turned on, etc Or does it seem like only the backlights go out?
Find a service manual, check the voltages coming out of the power supply
Then start checking the driver for the backlights
I found a few manuals and schematics at "toms service manuals " the ones LNxxB530 should all be the same except for LCD size

I had a plasma TV that quit working and it turned out to be caps on the audio board. Apparently they routed some major control circuitry onto the audio board for some insane reason so that if it goes out the TV cant function at all.




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