LG 50PC1DA problem

[Glitcher]

Re: LG 50PC1DA problem

Not sure if its just your camera or the actual tv itself, but the picture looks oversaturated in pink. (The pink suggests that the Z sus may be going bad)

But I had one of these sets before with a blown FET on the buffer board. Replaced it, and the TV worked normal again, however half an hour later the FET blew again... So replaced it again with an added heat sink, TV back to normal. Another half hour later.. TV started flickering or eventually gave no picture and a black screen. Turning it off for ten minutes and restarting it, the picture came back but the problem continued like that.

It seemed to be the Ysus board that was starting to go bad (IPMs probably needed replacing).

[coopigeon]

Re: LG 50PC1DA problem

Hold on -- could still be a Y-sustain fault. You'd want to check the -Vy, Vsc and Vzbias voltages to be sure... post a picture of the sustain boards if you need help with this.

Thanks tom .. i got a week off so ill strip it tomorrow and take a load of snaps. I take it the y sustain is different from the buffer boards i had done?
ill snap everything and post the relavant ones.

One thing i bever mentioned on my very first post but when i switched in on with original fault (the big white stripe) the tv would only stay on for about 8 seconds then a small pop and went off into standby. i would try it again and after a few switch ons it would stay on for good. since the FETS were done this has never happened so i guess i thought it may have been them being bad that switch it off

[coopigeon]

Re: LG 50PC1DA problem

Not sure if its just your camera or the actual tv itself, but the picture looks oversaturated in pink. (The pink suggests that the Z sus may be going bad)

But I had one of these sets before with a blown FET on the buffer board. Replaced it, and the TV worked normal again, however half an hour later the FET blew again... So replaced it again with an added heat sink, TV back to normal. Another half hour later.. TV started flickering or eventually gave no picture and a black screen. Turning it off for ten minutes and restarting it, the picture came back but the problem continued like that.

It seemed to be the Ysus board that was starting to go bad (IPMs probably needed replacing).

it might just be my camera as was in a darkened room to help emphasize what its doing. the still pic was when attached to a freeview recorder box and as far as i can remember the colors have allways been a bit messed up on that box but you also may be correct. this is becomming a nightmare lol

[coopigeon]

Re: LG 50PC1DA problem

Hi

i have taken some phots see below. Its on and working at the moment but when it starts to flicker there is a ticking noise coming from the y sus area ( the left hand side as you look at it . hard to see if its coming from the ysus itself or the attached buffer boards as they are attached. if you need anymore pics just let me know im at home all day. i have a multimeter turning up this evening for my use.

pic 2 and 3 are just half and half of pic 1 .


There is also a quite strong buzz tht sounds like its coming from the longer heatsink on pic 4 area. but this is there even when tv is working ok

also dont know if this is anything but whenever i turn it on it says poor signal and i have to retune the inbuilt freeview .not once have i been able to switch it on and the channels are there unless i use my external freevie recorder. however it may not be the greatest signal granted but when it is tuned theres hundreds of channels


i have left it on and so far it has not flickered at all in two hours , wonder is this is because the back is off and cooler

[tom66]

Re: LG 50PC1DA problem

Try using a hairdryer or hot air wand set to a low temperature - can you get the screen to flicker if either Z-sus or Y-sus are heated?

[coopigeon]

Re: LG 50PC1DA problem

Try using a hairdryer or hot air wand set to a low temperature - can you get the screen to flicker if either Z-sus or Y-sus are heated?

ok i have a hot air gun which ill try .am i ok to do thus with the set on ?

ill try thr ysus board first then the other one.

do i need to be heating the whole thing or a selected area?

thanks again for your replies..

its just started doing it after 3hrs for seconds then comes back on /off for a minute.

[tom66]

Re: LG 50PC1DA problem

You can do it with a hot air gun, but keep the temperature as low as possible and if it has any tip on it to focus the heat to a point, remove that. Keep it 3-4 inches from the board. I'd start in the area which is ticking.

[coopigeon]

Re: LG 50PC1DA problem

i am heating the ysus . It is flickering all the time now but has been since before i heated it.Shall I heat both boards up let them cool ?

[coopigeon]

Re: LG 50PC1DA problem

the ticking is almost certainly coming from this area somewhere around them fuses or under the top heatsink right next to it

[tom66]

Re: LG 50PC1DA problem

That kind of area suggests a Y-sus ER IPM fault. Alastair knows all about these...

[coopigeon]

Re: LG 50PC1DA problem

hi

this is the noise

https://dl.dropboxusercontent.com/u/...224_124927.mp4

and again after being on standby for ten mins i get a poor signal floating around the screen and no tv unless i retune

[coopigeon]

Re: LG 50PC1DA problem

update :

so i have been out and came back switched telly on. flickering straight away followed by it being ok for a few seconds on , off on , off then a pop and in standby , when i go to switch on the telly thinks about it then goes back to standby. something has definitely gone now , mulitmeter will be with me within an hour

[coopigeon]

Re: LG 50PC1DA problem

Ok i have multimeter at hand so if anyone can give me any guidance on how and what to check first that would be great .

thanks in advance

[tom66]

Re: LG 50PC1DA problem

With set powered on and flickering, check voltage across these capacitors on Y and Z-sus.
Expected range 80 to 120V steady, and matching other capacitor.
(You can test any in that bank - they are all in parallel.)

[coopigeon]

Re: LG 50PC1DA problem

With set powered on and flickering, check voltage across these capacitors on Y and Z-sus.
Expected range 80 to 120V steady, and matching other capacitor.
(You can test any in that bank - they are all in parallel.)

thanks tom , only one problem the tv now longer switches on after something popped this afternoon. light goes to white for about 6 seconds then back to standby and nothing at all comes on screen . something made a largish popping noise and it went off. im hoping this makes things easier to suss out with it not working as opposed to playing up

[coopigeon]

Re: LG 50PC1DA problem

can anyone shed any light on what i can check ?

thankyou

[tom66]

Re: LG 50PC1DA problem

I think the ER-IPM has finally failed. You will probably have to replace the Y-sustain which might not be cost effective for an older set like this, needs two new IPMs plus they need to be soldered onto the board which is very difficult. I couldn't do it with my gear...

[coopigeon]

Re: LG 50PC1DA problem

I think the ER-IPM has finally failed. You will probably have to replace the Y-sustain which might not be cost effective for an older set like this, needs two new IPMs plus they need to be soldered onto the board which is very difficult. I couldn't do it with my gear...

it sounds like im flogging a dead horse with this set now perhaps ?

[coopigeon]

Re: LG 50PC1DA problem

anyone got a manual for this one as ive convinced myself the pop came from the middle power board so just want o have a final look before binning it

[tom66]

Re: LG 50PC1DA problem

Maybe of use:
http://www.tgohome.com/ServiceManual...&Search=Submit

I wouldn't bin it, I see these go on ebay for around £50 with Y-sus faults so I'd stick it on there and maybe someone else will invest the time into fixing it. But they really are a pain in the arse to fix when the IPMs fail.