LG 42LD450-UA Powerboard replaced and still no power

[Betviper]

I narrowed the issue down (so I thought) to the powerboard. I purchased one online and installed it but still no voltage coming out the pins. I have checked the LEDs with an LED tester I purchased and they test good. I put the TV aside for quite a while but with this Corona crap I have some free time. I am by no means an electronics repair person but I do enjoy fixing anything and everything. I am wondering if the board I bought online is defective. I found this capacitor (guessing that's what it is) and it has 79v on one side and 0 on the other. Everything I have tested on the primary side of the board seems to be ok as far as I can tell. This capacitor that I am suspect about goes from the primary side to the secondary side of the board. Curious if I am right thinking it's bad since there's voltage one one side but not the other. Here is a pic of the part in question. Thanks in advance for any advice.

[nomoresonys]

Re: LG 42LD450-UA Powerboard replaced and still no power

Maybe put your original board back in and test that capacitor, see if it reads the same.

[R_J]

Re: LG 42LD450-UA Powerboard replaced and still no power

When you are measuring the 79v (ac? dc?) across that cap you are measuring ground cold ground to hot ground. The cap is fine.
Are you getting any standby voltage on the secondary?

[diif]

Re: LG 42LD450-UA Powerboard replaced and still no power

Your TV doesn't have LED backlights, it has CFLs, no you won't have voltage both sides of that cap.

[Betviper]

Re: LG 42LD450-UA Powerboard replaced and still no power

It was 79v AC. Maybe it's the beers but I'm not sure what you mean by "ground cold ground to hot ground". I measured it with the black lead on ground and the red lead on each leg of the capacitor. I tested other capacitors and they had voltage on both legs. This was the only one that did not. No standby voltage on the secondary at all.

My LED tester lit up the back lights and according to LGs website "LG 42” Class Full HD 1080p LCD TV (42.0” diagonal), 42LD450 +6 ... This energy efficient TV uses LED backlighting to deliver a brighter and more vivid picture." I've seen wrong info on manufacturers websites before though.

[nomoresonys]

Re: LG 42LD450-UA Powerboard replaced and still no power

How bout some good clear straight on pictures of each board and one of the whole back to see how they are connected.

[R_J]

Re: LG 42LD450-UA Powerboard replaced and still no power

This power supply/inverter board is for CCFL Lamps. If you believe the panel has led's you are wrong. The voltage output from the two transformers T703 & T704 is high frequency high voltage AC It will not operate LED's


The power supply has a primary side that is connected to the A/C line (see that dotted line on the board) that seperates the primary (HOT) side from the secondary (Cold) side. It is isolated from the a/c line so when you touch any exposed connections like the input jacks, you dont get a shock.

[budm]

Re: LG 42LD450-UA Powerboard replaced and still no power

You should recheck your FULL TV model number, your pictures in your post #1 clearly shows TWO HIGH VOLTAGE inverter transformers.
https://www.badcaps.net/forum/attach...5&d=1586026005
Please us pictures the whole back side of the TV showing all the boards.

https://www.shopjimmy.com/lg-eay6086...upply-unit.htm

[nomoresonys]

Re: LG 42LD450-UA Powerboard replaced and still no power

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