LG Infinia 60PZ750 Sound and Not Picture

[ElctroNYC]

Hello. I have a LG Infinia 60PZ750 . I change the Z-sustain board in my tv and it gives me sound but not picture. I disconnect the Y-sustain board and left the Z-sustain connected and it gave me sound but not picture then I disconnect the Z-sustain and connected back the Y-sus and again it gave me sound but not picture.
I check both fuses in the boards and they seem to be ok unless i am checking them wrong.
Could this be a y-buffer problem?
please help

Thanks in advance

P.s the z-sustain in this picture was the one that got replaced.

[ReeceyBurger123]

Re: LG Infinia 60PZ750 Sound and Not Picture

Does the screen appear to glow in a dark room ?

[ReeceyBurger123]

Re: LG Infinia 60PZ750 Sound and Not Picture

Normally on these if the Sus boards or buffer are shot the Tv will not start.

[ElctroNYC]

Re: LG Infinia 60PZ750 Sound and Not Picture

Does the screen appear to glow in a dark room ?

hmm didn't check that I will check that tomorrow. But at first sight I didn't see any glow.

[ElctroNYC]

Re: LG Infinia 60PZ750 Sound and Not Picture

Normally on these if the Sus boards or buffer are shot the Tv will not start.

yeah with the old Z-sus the tv will turn on and turn off in less than 2 or 5 seconds. At least now the tv stays on.

[ElctroNYC]

Re: LG Infinia 60PZ750 Sound and Not Picture

Does the screen appear to glow in a dark room ?

I checked and I didn't see any glow.

[freakaftr8]

Re: LG Infinia 60PZ750 Sound and Not Picture

Look at your Z sustain board on the bottom where the coils are is the board pretty darkened and are the coils making a bad solder connection to the bottom of the board cracked solder and very dull gray looking?

You never know if somebody told you a bad board. Also are all your screws in the Y and Z board in and tight? these TVs do not like to run if you have any screws missing from either board

[ljintexas]

Re: LG Infinia 60PZ750 Sound and Not Picture

can you tell me what the resolution was for this? I have one on the way in with this exact issue.

TIA

LJ

[Nick's Tvs]

Re: LG Infinia 60PZ750 Sound and Not Picture

If you didn't screw in all the screws on the board nice and tight after replacing it, you probably broke your new board. This is one of those boards where all screws needs to be in tight or else the new boards will go out instantly.
When these go out, they distinctly get an open fuse and like freakaftr8 suggested check the inductor solder joints. Those crack up pretty bad and your boards looks really dark next to them, so I really wouldn't be surprised if they are cracked.

[ljintexas]

Re: LG Infinia 60PZ750 Sound and Not Picture

I have it on the bench..I will attempt to fire it up..Previous owner reported sound and no pictures. Just found out I am road tripping next couple days..Yuck

[ljintexas]

Re: LG Infinia 60PZ750 Sound and Not Picture

Very nice looking set.

[ljintexas]

Re: LG Infinia 60PZ750 Sound and Not Picture

Just got back..will report findings shortly on initial fire up. Had to put my Mom in hospice care for her remaining days. Cancer is a terrible terrible disease.
At least she is resting comfortably.

[ljintexas]

Re: LG Infinia 60PZ750 Sound and Not Picture

Vs and Va are good. Fuse blown on z sustain. I do have audio and no video.
Going to pull Z sus and send it to Nick or PTS Electronics for repair.

[ljintexas]

Is this board repairable?

Looks kind of toasty but not too bad compared to some others I have seen that were definitely not repairable. Nick, I think this question is for you, buddy! if doable, it's coming your way. The stand-offs definitely need cleaning..they have what looks like carbon on them..Is alcohol and a q-tip acceptable or should I use tuner cleaner? A few of the screws were what I would call barely snug. Would it be a good idea to use some Loctite thread locker going back?

Thanks

[ReeceyBurger123]

Re: LG Infinia 60PZ750 Sound and Not Picture

Hmm I think your coil has broken though the solder lol Yes you can use IPA and cleaning swabs to clean the soot off. Also resolder them with alot of freah solder to help prevent future failures. Also take the Ysus out and preform the same repair on it.

[ljintexas]

Re: LG Infinia 60PZ750 Sound and Not Picture

I will go and remove the Ysus now for inspection..thanks Reecey!

[ljintexas]

Re: LG Infinia 60PZ750 Sound and Not Picture

Here are pics of the solder joints for the coils and the IGBTs on the Ysus. should I reflow them anyway?\
Thanks

LJ

[ljintexas]

Re: LG Infinia 60PZ750 Sound and Not Picture

Resoldered all coils, mosfets, igbts..main power caps. No discoloration anywhere on Ysus.

[ljintexas]

Re: LG Infinia 60PZ750 Sound and Not Picture

Nick will have Zsus today for repair..no evident heat on Ysus. Resoldered for 30 min on Ysus as suggested by Reecey. Damn thats alot of components on heat sinks!!

[Nick's Tvs]

Re: LG Infinia 60PZ750 Sound and Not Picture

You don't really need to get lock screws, the regular ones that come with the set are fine as long as you don't leave them loose. Just make sure all of them are placed back in the set nice and tight when you get your board back.