Lg 50pv350t

[sordids999]

hi guys

got this tv today totally dead but clicks twice from the psu but upon inspecting i noticed at the bottom left by the speaker there is a slight corrosion not sure if this is affecting the tv ,no VS/VA reading at all but if i unplug the main board i get VS reading on the psu at 110 volts but decreases very slowly to 0 volts no VA reading
testing more measurements now so will update as i go along

[sordids999]

Re: Lg 50pv350t

update:
330 volts of both main caps

[sordids999]

Re: Lg 50pv350t

update:
disconnecting the Ysus board from the psu now gives me 390 volts of the main caps also if i use the touch panel to turn the tv on the Ysus makes a slight screeching noise so checking over the Ysus now

[sordids999]

Re: Lg 50pv350t

Update:
Buffer boards checked for shorts but all good

[Shinju]

Re: Lg 50pv350t

http://www.toms-service-manuals.com/...h=Submit+Query

Shows the 50pv450 but I think they are very similar in how they work.

good place to start troubleshooting.

Its the 1# manual.

[sordids999]

Re: Lg 50pv350t

Thankyou

[sordids999]

Re: Lg 50pv350t

update :

ok so trying to test if the psu is good so i jumped via the mainboard cable with the picture i have uploaded and now VS VA is stable
so does this mean its the main board at fault ?

[Shinju]

Re: Lg 50pv350t

What does the voltages on your X and Y tell you?

[sordids999]

Re: Lg 50pv350t

Y-SUS P811 connector needs to be disconnected from the ysus upon testing the power supply then i get steady VS VA on the psu,but once i connect this back up with the mainboard still being jumped the psu just clicks again then i cant get no steady reading on X and Y

[Shinju]

Re: Lg 50pv350t

Gotcha, then its very possible your mainboard is not functioning proper. I see the corrosion on the speaker landing.

did you take the heatsink off that bottom buffer and inspect it for electrolysis damage?

[sordids999]

Re: Lg 50pv350t

ill do that now thanks

[Shinju]

Re: Lg 50pv350t

Cool, post some photos of it when you do please

[sordids999]

Re: Lg 50pv350t

picture uploaded but not good news theres a burn mark plus one corner of the the cable has burnt away was a struggle to get out must have arced itself inside
so im gathering the tv is not repairable ? and the biggest part is working out what i can salvage

[sordids999]

Re: Lg 50pv350t

any ideas ?

[sordids999]

Re: Lg 50pv350t

ok with disconnecting the following connectors/ribbons i now have VS/VA working fine on the Ysus and even the control board led is lighting up,so im thinking maybe the main board had a fault and after i switched it on and where the corrosion set into the buffers it blew ?
so im hoping i can now salvage the YSUS,ZSUS,PSU,Control board unless someone else thinks otherwise

thanks

[sordids999]

Re: Lg 50pv350t

picture :

[tom66]

Re: Lg 50pv350t

Is there a legend printed next to the connector going off to the main board? What's printed on that?

[sordids999]

Re: Lg 50pv350t

what connector do you mean tom?
plus i removed the buffer and there is quite a bit of corrosion under the buffer

[tom66]

Re: Lg 50pv350t

Make sure not to run the TV with the heatsink removed for the TCPs (brown ribbons) or the panel will fry.

The connector is on the power board and connects to the main board.

I can't quite see the corrosion you speak of? Are you talking about the white marking? How does that even happen, unless someone spills water down the back of the set...

[tom66]

Re: Lg 50pv350t

Oh... I see the damage now... damn... Hmm, might be repairable but could be difficult.

Maybe worth trying this. Get new XL buffer board. Install ALL but bad cable. Worst case you see everything work minus bar (or everything not work and you know boards are bad...) Maybe best case you can repair damage as it looks like only one track is broken... it would be difficult, but could could potentially scrape away damage and solder a wire across it.