Panasonic 7 Blinks Enigma

[ranergeo]

Re: Panasonic 7 Blinks Enigma

Sorry, it took me a minute to find C10, but I retested after an initial incorrect test, and yes, it does blink 8 times!

[tw2005]

Re: Panasonic 7 Blinks Enigma

My brain getting tired, 2 am here. Can you work out from the parameters whether that VAD is outside the detection trip? I worked it out once but now I'm not sure. Maybe leave that and try that next test and see if 8 blink

[tw2005]

Re: Panasonic 7 Blinks Enigma

Recheck, are you certain? It's in the manual.

It needs to be that one

[tw2005]

Re: Panasonic 7 Blinks Enigma

Good, order another SN from shopjimmy. That's where I'm at. Digest it youself first though.

If you're really brave, earth the SOS7 to cancel out the 4.? Volts and it may produce a picture but I'll leave that to you. Obviously if the SN was staying on and no smoke it's probably safe to try it. If you can work out VAD is wrong then try it . If it gets a picture then just shut it down and get a good SN.

there was a VSCAN det too wasn't there? Do you think we should find that and measure too?

Better hold off and think about what we've done. Because we started with SOS7 i'm wondering if that C10 isolation is still valid because it's part of the SOS6 fault isolation steps but adding your SOS6 with everything unhooked on the SN I still feel we're on th right path.

I am fatigueing here bad too tired.

[ranergeo]

Re: Panasonic 7 Blinks Enigma

Thanks tw2005, 'specially at this time of night/morning! I've attached the block diagram, which does show the VAD in the error detection circuit (although I honestly don't fully understand how it all interacts!) I may try the disable procedure... will this just smoke the SN board, or would it smoke something else? As you said earlier, if it takes out the SN board, I probably need to figure it was bad anyway!

Again, thanks for all the help!!

[tw2005]

Re: Panasonic 7 Blinks Enigma

I think that VAD is correct? Try TPVSCN and also measaure MID at SN3 with the SN running.

[tw2005]

Re: Panasonic 7 Blinks Enigma

I have no idea, learning can be painful and this is where if it was mine I'd have ago and just accept if it goes bad but measure those other points first.

If this was the old design then I'd disconnect the buffers and jumper the sc50 on the SC board.

But we don't have that luxury. Did you say you tested the buffer section with no shorts too?

I'm thinking smoking buffers at worse but that's still going leave a faulty panel as a possibility. Last time I got brave to suggest something like this (ryan74) his buffer smoked but he's since found a shorted panel.

Other option , give it a break and get more opinions. It's still a bit of a jigsaw puzzle.

If tha VAD was wrong I'd be more confident

[ranergeo]

Re: Panasonic 7 Blinks Enigma

I checked the pins on SC3 with 15VDC at each, and the VSCN had -47.5VDC.

I agree that I might take a bit of a break, as the only thing with smoke coming from it are my ears... a sure sign of brain-fry! I'd love to be able to isolate out the panel, but it looks as if it needs to be connected to prevent SOS codes.

I'll double check the buffer section, but everything looked ok, and didn't look like much to test!

Thanks again!

[tw2005]

Re: Panasonic 7 Blinks Enigma

Well that's now even more confusing, -47.5v. 125-166V is where it needs to be. Maybe it's not active with what we're trying, If it was the panel would be on I guess. And MID

Under normal operation, the output voltage (MID) of the “Energy Recovery” circuit ranges between 68V and 138V. If the voltage drops below 67V or increases above 139V, the error detect circuit (IC16581) is triggered. This causes a high to be output to pin 21 of connector SC20.

That's for the 42S2 but would be a good guide though(training manual)

[tw2005]

Re: Panasonic 7 Blinks Enigma

scn_pro ?

[ranergeo]

Re: Panasonic 7 Blinks Enigma

Hmm, I figured the -47V was due to passing through the transformer before the test point (that is a transformer in the block diagram, right?? Sometimes I get a little confused at what I'm looking at!), while VSCN and SC1 should show the full 190VDC, as it is a straight shot from the Vsus input.

Are you also saying that the MID voltages should have been between 67-139? Would that point to a power board problem?

I need to step out for a bit, but will jump back on this once I get home! Thanks again for all the help in tracking this down!

[tw2005]

Re: Panasonic 7 Blinks Enigma

See if the resistance tests can be translated to the SN from that training manual.
I find a lot of the time panasonic give the same part location numbers across the range.

VFG & L851

VFG (Floating ground) and pin 3 of IC724 (IC16724)

Etc.

[tw2005]

Re: Panasonic 7 Blinks Enigma

If you have 5v,15v & 190V (VS) no it won't be PSU

I don't see what you mean but they are 2 different points with a diode in between and Vscn coming out of an IPD Regulator MIP3910 (7pin DIP).

VSus goes into the SN and it then generates other voltages, waveforms etc.

The schermatic is where you need to look for fine detail, not sure if you're getting confused with the block diagram which breaks it down to sections not components.

Where's an engineer when you need one?

[ranergeo]

Re: Panasonic 7 Blinks Enigma

Alrighty! I have a schematic, a meter, and a troubleshooting guide... this is what I've found for most of the readings:

VFG to IC724 (pin 3) - 330 KOhms (190+ KOhm normal)
VFG to TPSN1 - 330KOhms (approx 2.6Kohm normal)
VFG to 5V F (tested@ IC724 pin 2) - 330Kohms (190+ Kohm normal)
VFG to "SM" VFO (@TP97) - 330KOhm (should be 4Mohm, but it is a detached board test, which I can't do)

Unfortunately, the last 2 tests are supposed to be "buffers detached" tests, which isn't possible with the SN integration. Interestingly, there were some more notes in the schematics noting the necessary voltages, and what would trip the SOS detection. I'm going to try to make sense of it, and figure out how to test it...

I've attached the info I found.... any thoughts where to start looking now??

[ranergeo]

Re: Panasonic 7 Blinks Enigma

After realizing that I wasn't going to figure much out chasing my tail around the SN board, I decided to try once more to replace out the SN. However, I read that it was best to also replace the SS board when doing so, as one tech mentioned that a bad SS would damage the new SN.

After putting in the new boards, powering on resulted in a quick flash on the screen as it powered up, a short buzzing sound from the SS board, and a 10 blink code (changed from the 7 blink code I previously had). Using the Panasonic trouble chart for 13th Gen plasmas, it led me back to the SS board.

My question is this, trying to determine if it is the panel or not, I also tried to disconnect the ribbons that go from the SS to the panel, and noticed no change. Would this indicate that the panel is probably ok, and it's just a bad SS i received?

Thanks!

[V3dran]

Re: Panasonic 7 Blinks Enigma

If I'm not wrong if it's all ok your tv should turn on without the SS board with a blurry picture

[tom66]

Re: Panasonic 7 Blinks Enigma

Not on a Panasonic -- it will just throw out an error code.

[Auscom]

Re: Panasonic 7 Blinks Enigma

Question. 7 red blinks. TH-P55VT30A SOS TP voltage on boards. The service manual does not state the normal non-SOS condition voltage at any SOS Test Point on any board. The Main A board monitors the SOS lines. I have 5VDC on both the SC and SS boards SOS TP. Does anyone know if the A board looks for the absence of 5VDC on the SOS test points to trigger a shutdown or is it the presence of 5VDC at the SOS test points?

[kasfamily]

Re: Panasonic 7 Blinks Enigma

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