No background on the TV. The light on the front flashes red, blue 2X and then stays blue. I took the back off, I had it laying screen down on my coffee table and powered it on. When I did, it made a little static noise and I looked to see if there was any picture (there wasn't) and then I noticed two resistors glowing orange/red on the Zsus (part # 50G2A_Z). Is the board repairable and is the fault within that board or is it caused by something else?
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Re: LG 50PQ20 Plasma no pic/no sound
The Z-sus is a common failure on this model.
I think someone has a repair kit but you can buy the board too
http://www.ebay.co.uk/sch/i.html?_tr...at=0&_from=R40Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search. -
Re: LG 50PQ20 Plasma no pic/no sound
Is the failure (most likely) isolated to this board and what parts would I need to repair the board (just the resistors?)?Comment
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Re: LG 50PQ20 Plasma no pic/no sound
It is most likely isolated to that board but some tests can be made. You will need a digital multimeter, do you have one?
As far as repair goes it is probably those two resistors plus associated components like FETs, driver ICs, diodes, etc. If you can locate all the failed parts it can be considerably cheaper than replacing the board but sometimes it is not worth the time because if you miss one component, all your new components can possibly go back up in smoke.
Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.Comment
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Re: LG 50PQ20 Plasma no pic/no sound
Yes I do have digital multimeter. And let me add that I have tested the power out on the psu board and all the v were correct. While I am awaiting your response I'm going to check if I have any audio now with the Z-sus disconnected.
Side note:
Parents of the world need to raise more people like tom66. A person who is willing to help others learn information he (likely) paid to obtain, is a trait that's exceedingly rare.Last edited by pk7tanner; 04-21-2013, 08:26 PM.Comment
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Re: LG 50PQ20 Plasma no pic/no sound
tom66 if Z-sus board is the only issue/if I am able to fix this TV, how should I expect it last? Is there a way to prolong the life of this TV? I'm fairly good customizing/moddingComment
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Re: LG 50PQ20 Plasma no pic/no sound
thanks for your helpComment
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Re: LG 50PQ20 Plasma no pic/no sound
Found a board on ebay for $14.00 incl. s/h with 30 day warr. So i figured it's worth the risk. I'll let you know how it turns out. thank againComment
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Re: LG 50PQ20 Plasma no pic/no sound
Good luck. I never paid for any of this information though. It's all learned from experience -- over 50 TVs so far and counting. The service manuals in my signature are all sourced from the manufacturers directly, sometimes through other TV technicians.Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.Comment
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Re: LG 50PQ20 Plasma no pic/no sound
Well I was should've known what I didn't check would be the problem (US Air Force better not let anymore Murphy's make laws). It's the Y-sus and I am going to attempt to repair the board myself. Any tips?Comment
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Re: LG 50PQ20 Plasma no pic/no sound
You haven't yet provided pictures of the layout of the TV, I'm not sure if this TV uses combined energy recovery which sometimes requires both Z-sus and Y-sus to be repaired or replaced at the same time.Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.Comment
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Re: LG 50PQ20 Plasma no pic/no sound
Not knowing the the history of the TV proved to be part of the issue, the Y-sus board has obviously been worked on by someone w/o much skill. I didn't know I was expected to provide pics. Sorry
pics
1 back of tv
2 Y-sus
3 Z-sus
4 Pwr BrdAttached FilesLast edited by pk7tanner; 04-25-2013, 07:16 PM.Comment
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Re: LG 50PQ20 Plasma no pic/no sound
Looks like it's independent ERC to me; good, as that usually means failure is constrained to one board or the other.
As far as repairing the Y-sus, look at each component and test for shorts.Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.Comment
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Re: LG 50PQ20 Plasma no pic/no sound
When I took the Y-sus board off and saw the the work that had been done to it, I knew that was where my problem.
I'm having a tough time reading the service manual for this model on my computer. Will it make more sense if I print it out and look at it next to the boards? The reason I'm asking is the previous owner replaced some resistors & I'm not certain they are the correct valuesComment
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Re: LG 50PQ20 Plasma no pic/no sound
That would work, maybe. Have you seen this diagram yet?
http://tgohome.com/ServiceManuals/?d...&Search=Submit
I wish I had a diagram of the panel layout -- LG produce nice ones. This is a PDP50G2 panel, I think.Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.Comment
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Re: LG 50PQ20 Plasma no pic/no sound
Thank you. I wasn't sure which one most closely resembled the unit I have. It's too late to do anything right now, but hopefully that will guide me in the right direction.Comment
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Re: LG 50PQ20 Plasma no pic/no sound
I replaced a few resistors (3 total on the Y-sus: 1 toasted, 1 had broke & 1 looked suspect) on the Y-sus. When I plugged it in with all the boards connected, nothing started smoking. The power LED doesn't flash like it was. I don't have any display, but I do have some faint audio.
What should I try next?Comment
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Re: LG 50PQ20 Plasma no pic/no sound
Check if you have Vs coming out from the PSU with boards connected.Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.Comment
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Re: LG 50PQ20 Plasma no pic/no sound
Do you mean volts? The TV wouldn't power on if I didn't. Which pin should I check? I cant believe there isn't an onboard diagnostic program on those TV. Do you know what the software for the USB connection is calledLast edited by pk7tanner; 04-27-2013, 06:36 AM.Comment
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Re: LG 50PQ20 Plasma no pic/no sound
There's very little diagnostics an LG TV provides.
I mean measure the Vs output on the power supply with everything connected, do you see anything?Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.Comment
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