LG 60" 60pv250 sound but no picture

[eliteconcept]

Start off by saying, I will post pictures of the boards later today for better support.

TV will power on, i can hear sound, but no picture on screen.
In a dark room it doesn't appear there is any light on the screen at all.
Does not appear to have any obvious damage on any of the boards on first inspection.

After some searching seems like it might be a Y Sustain board issue? I tested the VS voltage to the Y Sus board and got 201 v seems like other posts asked for VS readings. But really don't know how to further troubleshoot this. Looking for some guidance and advise. Again will post pictures of boards later for further input.

Thanks in advance

[Hamie]

Re: LG 60" 60pv250 sound but no picture

Check my post in this thread.
Do the same tests and post results.

https://www.badcaps.net/forum/showth...020#post571020

[eliteconcept]

Re: LG 60" 60pv250 sound but no picture

Thanks for the info.
Here is what i got from my readings

VA 52 label says should be 55
VS 201 label says should be 201
VY -64.5 label says should be -178
VSC 0 label says should be 150
z bias 0 label says should be 110


So would this be indicative of bad power supply or bad Z and Y sus boards?

[Shinju]

Re: LG 60" 60pv250 sound but no picture

Sounds like a bad ZSUS, did you put both + and - probes from your DMM on the + and - pads for VSC, VY and VZB?

[eliteconcept]

Re: LG 60" 60pv250 sound but no picture

yes i used the test points on each board and put the leads on them to test. tv was turned on at the time as well

[Hamie]

Re: LG 60" 60pv250 sound but no picture

Ok unplug the buffer boards form the y-sus and measure the voltages again.

[Hamie]

Re: LG 60" 60pv250 sound but no picture

Also we need pictures so we can see how the boards are linked together.
Note: the voltages might only appear momentarily then drop off once the TV detects a problem. So you'll need to either measure the voltages quickly, or get someone to turn the TV on and off whilst you measure them.

[tom66]

Re: LG 60" 60pv250 sound but no picture

Sounds like a bad ZSUS, did you put both + and - probes from your DMM on the + and - pads for VSC, VY and VZB?

Bad Y-sustain or buffers I'd say, given the Vsc/-Vy is low.

[eliteconcept]

Re: LG 60" 60pv250 sound but no picture

you guys are awesome. I didn't have good lighting to post pictures yesterday. Will post a pictures later after i'm off work. Many thanks!

[Shinju]

Re: LG 60" 60pv250 sound but no picture

Bad Y-sustain or buffers I'd say, given the Vsc/-Vy is low.

Possible, when I did my 60PV450 VSC/-VY was low and the Zsus was bad.


Also, check the solider joints under the large inductor coils on the Y and Z boards they fail/crack a lot.

These are good panels, I have 2 of the 60PV450s on my game room wall!

[eliteconcept]

Re: LG 60" 60pv250 sound but no picture

here is a picture of the all the boards

[eliteconcept]

Re: LG 60" 60pv250 sound but no picture

I examined the bottom side of the z sus board and noticed this solder joint looked like its shorted to another trace on the board, but wanted to post it to ask if thats what it looks like. Its the area where there are 3 larger solder joints in 2 rows, these 6 large joints below to the large inductor coils. It looks to me like one of the middle joints has shorted. Am i looking at this correctly?

[Shinju]

Re: LG 60" 60pv250 sound but no picture

All of those look cracked and loose, you can try soldiering them back to whole again but if they have gotten that bad I am sure they have cause damage to other components.

Mine was like yours and took out several SMD components so I just got a replacement board. There are 2 version of the y and z boards the version you have and the other listed on shopjimmy, they are interchangeable I using the newer versions with my panel and it's been working perfectly for almost 6 months.

[eliteconcept]

Re: LG 60" 60pv250 sound but no picture

Ok unplug the buffer boards form the y-sus and measure the voltages again.

Ok unplugged the buffers from y-sus and measured again


VA 52 label says should be 55
VS 201 label says should be 201
VY bounced all around when first turned on. anywhere from -5 to -65, after being on for about 2 mins did another reading and read 0. label says should be -178
VSC same thing as VY bounced all around when first turned on. reading after 2 mins read 0. label says should be 150
z bias when first turned on slowly ramped up to about 1 but then dropped back to 0, label says should be 110

any thoughts?

[Hamie]

Re: LG 60" 60pv250 sound but no picture

Looks like you have a faulty y-sus

Check the heatsinks for shorts.

[Terryfictv]

Re: LG 60" 60pv250 sound but no picture

Replace all six FGPF4533 IGBT's ( 2 sets of three ).
Upgrade to FGPF4536, order from Mouser. And be sure you re-solder
the coil connects !
For more info, take a picture of the whole board bottom side!

[MVC]

Re: LG 60" 60pv250 sound but no picture

Replace all six FGPF4533 IGBT's ( 2 sets of three ).
Upgrade to FGPF4536, order from Mouser. And be sure you re-solder
the coil connects !
For more info, take a picture of the whole board bottom side!

Hi, sounds like you know this TV. It is pretty much same as 60PV450, which I have a problem with.

While many Z-Sus go bad with shorts and burned things, mine is outwardly OK looking. If Z-Sus and Y-Sus use similar components, I am curious if you know what pieces are likely culprits and what I could test to narrow down.

As there are no used or new Z-Sus boards for these available I will either have to fix or get fixed and just need to know which components are likely.

https://www.badcaps.net/forum/showthread.php?t=47776

This post by terryfictv interests me because I have noted that the 60PK250 has few Z-Sus failures and plentiful supply or replacements while the 60PV250 and 60PV450 seem to have much more trouble and no boards available. If I have to replace pieces anyway, I would love to use more robust ones.

Look forward to any help I can get.

[eliteconcept]

Re: LG 60" 60pv250 sound but no picture

Looks like you have a faulty y-sus

Check the heatsinks for shorts.

Thanks. Just curious as i want to learn as well how do you know now its faulty y sus?

[Hamie]

Re: LG 60" 60pv250 sound but no picture

Out of interest is the control board LED blinking once every six seconds?

[eliteconcept]

Re: LG 60" 60pv250 sound but no picture

should i plug buffer boards back into y-sus then check for the blinking led?