LG 37LC2D No picture, believe bad power supply

[selldoor]

Re: LG 37LC2D No picture, believe bad power supply

Please post pictures of your board so we know what we are looking for

Welcome to the forum-
We can help a lot more if you please post good clear pictures of the whole chassis, and then pictures of each board, front and back (in the same orientation) and close up of connectors, (max resolution 2000x2000 and 2MB) using the manage attachments button, which is found by clicking "go advanced" under quick reply.

Please do not post inline and offsite as they slow down the loading of pages.

Examples of what is needed

https://www.badcaps.net/forum/attach...7&d=1280167246

https://www.badcaps.net/forum/attach...6&d=1280167246

https://www.badcaps.net/forum/attach...4&d=1280167246

It will be useful if you can say what the supposed fault was and a bit about yourself - skills tools etc.

[jamesharris]

Re: LG 37LC2D No picture, believe bad power supply

Please post pictures of your board so we know what we are looking for

Welcome to the forum-
We can help a lot more if you please post good clear pictures of the whole chassis, and then pictures of each board, front and back (in the same orientation) and close up of connectors, (max resolution 2000x2000 and 2MB) using the manage attachments button, which is found by clicking "go advanced" under quick reply.

Please do not post inline and offsite as they slow down the loading of pages.

Examples of what is needed

https://www.badcaps.net/forum/attach...7&d=1280167246

https://www.badcaps.net/forum/attach...6&d=1280167246

https://www.badcaps.net/forum/attach...4&d=1280167246

It will be useful if you can say what the supposed fault was and a bit about yourself - skills tools etc.

Ya, ok. The psu is identical to others previously posted in this thread. The original fault was NP/NS. I recapped the board (power supply) as I have done previously but this time I inadvertently took a few caps out without noting where they came from. I'm pretty sure they're all back in their right spots but I'm missing the 6v rail. No schematic is available for this model and it's difficult to trace the tracks.
I've been in and around electronics for the past 20yrs and have a tertiary qualification ( electronic trade) and a fully equipped toolbox, dmm, cro ect. Don't do many tv repairs, but the ones I've done have been successful.

[fire7655]

Re: LG 37LC2D No picture, believe bad power supply

Hello, I am having the same issue as every else on this thread. The only thing is that none of the capacitors are bulging. If anyone has any solutions, it would be greatly appreciated.

[tom66]

Re: LG 37LC2D No picture, believe bad power supply

Check the +3.4V line, sometimes the capacitor or IC can fail, without obvious signs.

[fire7655]

Re: LG 37LC2D No picture, believe bad power supply

I am new to all of this stuff. So, what exactly should I check and how?

[tom66]

Re: LG 37LC2D No picture, believe bad power supply

Can you post a picture of the power supply connector going to the main board(s).
The main board on this model is the one with HDMI.
The power supply goes directly to the mains power input.
I have worked on the UK version of this set which is different, it had low +3.4V causing many odd problems.

[fire7655]

Re: LG 37LC2D No picture, believe bad power supply

When I opened it up I saw three boards. You are talking about the middle board, but I am not sure what connector you want. here is a picture of the entire thing.

[tom66]

Re: LG 37LC2D No picture, believe bad power supply

In this case I am interested in the pale yellow board. That is the power supply.

[fire7655]

Re: LG 37LC2D No picture, believe bad power supply

ok. Here are a few pics. One is the top and the others are the underside of it.

[tom66]

Re: LG 37LC2D No picture, believe bad power supply

Excellent clear pictures, thank you.

Do you see the pins marked 3.4V on the PSU?

You will need to install the PSU in the chassis, and use a DMM (digital multimeter) to measure the voltage, with all connectors connected.

When the connectors are connected there will be a small bit of metal exposed on the edge of the pin sheath.

You want to use the red probe to measure and keep the black probe in the TV chassis. Set your meter to DC 20V and note the reading you get in your reply.

[fire7655]

Re: LG 37LC2D No picture, believe bad power supply

Ok I found what you are describing. mine actually says 3.3v though. I will need to locate my multimeter tomorrow and test it.

[tom66]

Re: LG 37LC2D No picture, believe bad power supply

Oh OK, they may have changed it in future design. There is a pin marked 3.4V_ON (or 3.3V_ON) test this one too.

[fire7655]

Re: LG 37LC2D No picture, believe bad power supply

Ok so I just tested the points that you said. If I did it right, there were 4 points that I needed to test. In the picture I circled the one that was good in green and the bad ones in red. The bad ones were reading about 2.5v.

[Gadjet]

Re: LG 37LC2D No picture, believe bad power supply

Been following this post and started out with just about the same problem TV power led would blink 16 times then nothing no backlight anything. Ordered a used power supply and now I get a backlight and it was working. Hooked up a bluray player and it started flickering saying connecting. So I turned off the TV and turned it back on now it's just the backlight can't change the inputs or anything. Oh yeah the led still blinks green before the backlight comes on.

[tom66]

Re: LG 37LC2D No picture, believe bad power supply

Yep, your fault is with the 3.3V.

You can replace the PSU (I got one for £30/$45 shipped because I damaged mine trying to repair it) or you can attempt a repair. As far as I know, no-one here yet knows what causes the low +3.3V. On mine it measured just 1.5V!

[jh20]

Re: LG 37LC2D No picture, believe bad power supply

Yep, your fault is with the 3.3V.

You can replace the PSU (I got one for £30/$45 shipped because I damaged mine trying to repair it) or you can attempt a repair. As far as I know, no-one here yet knows what causes the low +3.3V. On mine it measured just 1.5V!

yep, same here.

gadjet, don't know how much you paid for your "used" power supply, but a brand new one is not too expansive at all, as long as you buy from the "right" place.

edit: from memory it cost me less than australian $60, + shipping on top of that.

[fire7655]

Re: LG 37LC2D No picture, believe bad power supply

tom66, where did you get your psu from. Everywhere I looking says that they don't have any.

[tom66]

Re: LG 37LC2D No picture, believe bad power supply

A recycling parts supplier in the UK.

[budm]

Re: LG 37LC2D No picture, believe bad power supply

Is this the same? There are A, B, C, D.
http://www.shopjimmy.com/lg-67099000...wer-supply.htm
I did not look through this long thread to find out exactly what you have.

[Gadjet]

Re: LG 37LC2D No picture, believe bad power supply

Thanks guys, yep the one cap had a slight bulge and I ended up replacing it everything started working just fine I've let the tv run for a full day now.