Re: Panasonic 42" TC-P42S30 *almost* fixed. 14 blinks -> snowy image bad color
I suppose that's fair for them to protect their schematics. That is really detailed IP. Are you offering the 50GT30A manual or do those schematics have the same issue? If it has the same structure and I can read the net names it might help me. Basically I just want to find the connections from my probing point to VAD, GND, and VSUS and see which devices to check. I could do it with what I have now but it will take some time. I should be able to spend some time on this tonight....
raftman
Member
Last Activity: 01-20-2016, 09:15 AM
Joined: 03-25-2015
Location: Ann Arbor
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Re: Panasonic 42" TC-P42S30 *almost* fixed. 14 blinks -> snowy image bad color
thank you - I will study the schematic a bit and test a few relevant components. My original compliant still stands - the schematics in the service manual have unreadable REFDES and net names! Are better, readable versions available?...Leave a comment:
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Re: Panasonic 42" TC-P42S30 *almost* fixed. 14 blinks -> snowy image bad color
I used a heating gun and added flux to the pad before reheating. When they were hot I brought in some solder to the tab (the bottom pad) and watched some solder get sucked underneath the part. I think the soldering connections are good. Soldering problem was my first thought too. I'll try next to check the driver IC after reviewing some other threads that might be helpful.
I annotated my original plot since the voltage scales weren't well labeled....Leave a comment:
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Re: Panasonic 42" TC-P42S30 *almost* fixed. 14 blinks -> snowy image bad color
TPVAD has similar looking pulses. I'm attaching a zoomed in image. Does someone have reference waveforms or could someone describe what they should look like?
BTW - Vsus is clean at ~215V....Leave a comment:
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Re: Panasonic 42" TC-P42S30 *almost* fixed. 14 blinks -> snowy image bad color
On TPSN1 there are series of pulses that repeat at 60Hz. I'm measuring TPSN1 with respect to ground (using the P2 connector). The pulses change between about 3 levels (-50V, 200V, 300V, approximately). The series of pulses lasts about 8ms, then the -50V remains until the next period begins.
Could anyone tell me what I should be seeing here? I've read a little bit about how the pixels are reset and cleared, but I have no idea if this waveform is bad or not.
Or...Leave a comment:
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Re: Panasonic 42" TC-P42S30 *almost* fixed. 14 blinks -> snowy image bad color
I had already tired both VSUS settings in service mode and the high mode did not look much better.
I borrowed a scope and took measurements at TPSN1 and and TPVAD (probe points shown in attached images). On the schematic there are notes by TPSN1: "Reference Voltage Vscn:147 +- 3V" and by TPVAD: "Reference Voltage VAD: 205 +-5V.
I do not think these test points are the reference voltages, as they have some transient activity (scope images coming,...Leave a comment:
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Re: Panasonic 42" TC-P42S30 *almost* fixed. 14 blinks -> snowy image bad color
Vsus measures at 213V at P2 with a DC meter. That seems reasonable correct? Some of the components I mentioned I believe control the negative voltage discharging of panel. I can borrow a scope if necessary.
There is a resistor labeled 'tpvad'. The voltage across this resistor, R838, is 188V DC. I think this node is doing something AC since measuring wrt ground gives changing values on dc meter. Schematic says Vad should be 205V +-5, so maybe low if I'm measuring correctly?...Leave a comment:
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Re: Panasonic 42" TC-P42S30 *almost* fixed. 14 blinks -> snowy image bad color
1) What voltages should I check? Vsus (across p2 or sn2)
[B]ok - can do tomorrow.[/B]
2) Which components should I check? I don't know, was the SS bad or not?
[B]SS board currently in TV is fresh from SJ. The old SS board did not illuminate the green LED. Per another post somewhere and the service manual I replaced both SN (only replaced components listed in OP) and SS simultaneously. Short answer I don't know if the old SS board is bad or not - I believe...Leave a comment:
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Panasonic 42" TC-P42S30 *almost* fixed. 14 blinks -> snowy image bad color
Greetings! I picked up this tv with a 14-blink no power condition. After some research I decided to replace the SS board and rework the SN board, using the repair kit from ShopJimmy).
Now the TV powers on (good), both green LEDs are on for both the SN and SS boards (yay), but the image quality isn't right (bad). Picture attached. You'll see colored, snowy pixels. I ran the self test mode and everything it reported was 'OK'. I can run any test patterns and access the service mode if that will help. I had to adjust many parameters - like R-cut, B-cut, G-cut, R-drv, B-drv, G-drv, etc... -
Re: New Members - please post your introductions here
Greetings! I've been working on a 42" Panasonic Plasma and came across this forum in my searches.
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