Re: Panasonic TX-P42U30B Service Manual
Thats not a bad price, These boards are a bit of a pain to do, so many things can and do fail on 'em....
I replaced 8 IGBT's, (6 x 30F131, 2 x DG302) 6 SM Resistors, 1 Driver Transistor pair, and 1 driver chip.
First run was with the V-SUS supply (White wire of the main supply to SN Board) wired in series with a 150W 240V inky-lamp as a precaution to other unseen faults killing the board again.
The set performed OK on dark images and those of medium brightness. During bright scenes--especially with advanced brightness/contrast settings, the SN board drew enough current to glow the lamp, lower the voltage and give a weird, mal-discharge, pink picture-- All due to the lowered VSUS at the SN board.
VSUS on my set was set to 'Low' in the engineer-settings, but is still at 217V.
During high brightness the voltage at the board would drop to 140V (as the lamp bulb glowed)
--There's a VSUS pre-set on the PSU, I set this down to 107V--its minimum setting and removed the bulb.
--Set performed normally. A test of the VSUS as outlined in the manual using white-screen indicated no issues of dead-pixels at the lower (107v) VSUS voltage, so that's where its gonna stay....
Trouble is with these series sets, the boards run extremely hot, the devices on them age prematurely and fail.
--Its just Bad Design in my opinion.
I too have now restored my board to full operation, but have installed various measures to keep this and the SS board cooler, as I believe this is the main cause of their failure.
I first installed some dead-toad-pads (silicone heat conductive pads) but all this did was make the plasma panel extremely hot in the area of the SN board and was worried of a local crack developing, so I fitted a small silent fan to the board above the hottest area too. This plasma panel has a steel backing that isn't that thick so not a very good sink of heat
Instead of an average temp of 70 degrees C, it now runs around 25-30 degrees at the devices average, after an hours test-time and doesn't heat up the panel.
These measurements were taken in a cool (15 deg C) room, I dread to think how hot this board would get in an overly heated house, or a hot climate with no cooling added!....
I just need an unscratched front-glass pane (screen protection/smoked glass) as the set currently doesn't have one--I removed it as it had a very severe scratch more or less dead centre.
Amazing the brightness of a Plasma picture --without this smoked glass pane in front of it, but in a well lit/bright room, doesn't look so good....
Thats not a bad price, These boards are a bit of a pain to do, so many things can and do fail on 'em....
I replaced 8 IGBT's, (6 x 30F131, 2 x DG302) 6 SM Resistors, 1 Driver Transistor pair, and 1 driver chip.
First run was with the V-SUS supply (White wire of the main supply to SN Board) wired in series with a 150W 240V inky-lamp as a precaution to other unseen faults killing the board again.
The set performed OK on dark images and those of medium brightness. During bright scenes--especially with advanced brightness/contrast settings, the SN board drew enough current to glow the lamp, lower the voltage and give a weird, mal-discharge, pink picture-- All due to the lowered VSUS at the SN board.
VSUS on my set was set to 'Low' in the engineer-settings, but is still at 217V.
During high brightness the voltage at the board would drop to 140V (as the lamp bulb glowed)
--There's a VSUS pre-set on the PSU, I set this down to 107V--its minimum setting and removed the bulb.
--Set performed normally. A test of the VSUS as outlined in the manual using white-screen indicated no issues of dead-pixels at the lower (107v) VSUS voltage, so that's where its gonna stay....
Trouble is with these series sets, the boards run extremely hot, the devices on them age prematurely and fail.
--Its just Bad Design in my opinion.
I too have now restored my board to full operation, but have installed various measures to keep this and the SS board cooler, as I believe this is the main cause of their failure.
I first installed some dead-toad-pads (silicone heat conductive pads) but all this did was make the plasma panel extremely hot in the area of the SN board and was worried of a local crack developing, so I fitted a small silent fan to the board above the hottest area too. This plasma panel has a steel backing that isn't that thick so not a very good sink of heat
Instead of an average temp of 70 degrees C, it now runs around 25-30 degrees at the devices average, after an hours test-time and doesn't heat up the panel.
These measurements were taken in a cool (15 deg C) room, I dread to think how hot this board would get in an overly heated house, or a hot climate with no cooling added!....
I just need an unscratched front-glass pane (screen protection/smoked glass) as the set currently doesn't have one--I removed it as it had a very severe scratch more or less dead centre.
Amazing the brightness of a Plasma picture --without this smoked glass pane in front of it, but in a well lit/bright room, doesn't look so good....
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