Re: Panasonic TC-P55S60 multiple black bars
Update: the bars have shown up 3 or 4 times in the last few months, now a different problem. Set is shutting itself off & giving the 8 blink. If I disconnect & reconnect the power cord it will work fine for hours on end. Starting to wonder if both of these issues are related, possible A board failure?
Stryff
Member
Last Activity: 12-21-2021, 07:11 AM
Joined: 10-19-2013
Location: Greenfield, WI
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Re: Panasonic sc tnpa5081 rebuild
I ended up sending my board to PTS, they did an excellent job & I had even removed components before sending it to them... looked factory. Although my board didn't have a burned trace!Leave a comment:
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Panasonic TC-P55S60 multiple black bars
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So the dreaded black bars have appeared on my set. As you can see from the picture it is at least the left 2 sets of ribbon cables. I re-seated them this morning and the problem reappeared after a couple hours. They both turn black at the same time so I'm leaning toward a board issue. It is very intermittent & doesn't seem to last long, any ideas? This is the 2nd Panasonic plasma of mine that has taken a dump in a total of 6 years, both had problems right at the 3 year mark... what a shame. The picture quality is hard to beat.... -
Re: Panasonic sc tnpa5081 rebuild
I can tell you since day 1 with my set, it had noticeable buzzing from the SC side, especially under high load (white screens). Not sure if that is intended but with my S60 it is near silent....Leave a comment:
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Re: Panasonic sc tnpa5081 rebuild
Ah it can be done, a small conical tip and thin solder go a long way. A day without sugar & caffeine helps too haha....Leave a comment:
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Re: Panasonic sc tnpa5081 rebuild
Ah I see where the resistance is coming from, I should've checked the schematic first. The FET driver IC521 has that resistance when I removed it from circuit.Leave a comment:
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Re: Panasonic sc tnpa5081 rebuild
Well Q551 is toast, seeing 500 ohms across pin 4 to 5 emitter junction when out of circuit. Pulled Q521 actually seems ok out of circuit, the 2 to 3 pads are still seeing 277ohms...Leave a comment:
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Re: Panasonic sc tnpa5081 rebuild
Ok I'll check out the SS board thanks for the heads up. I have 78L05 SMDs at work come to think of it. Q622 & Q621 seem to be ok, the only lower resistance I see is 47k across emitter to insulated gate, which looks like it should read be with R763 being there.Leave a comment:
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Re: Panasonic sc tnpa5081 rebuild
I'm open to any ideas.
Vin to gnd is about 28meg....Leave a comment:
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Re: Panasonic sc tnpa5081 rebuild
Q660 has indeed seen better days. Here's the readings from Q521:
1-2: 2.66k (charges up)
1-3: 2.86k (charges up)
1-4: 49k
2-3: 277ohms
2-4: 47k
3-4: 53k
Haven't checked online for parts yet, if I have to wait for Nov for the dual transistors that's fine. Also, the smaller 5V reg (IC771) is showing 5.6k across Vout & gnd when removed from circuit... I'm guessing that's shot?Leave a comment:
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Re: Panasonic sc tnpa5081 rebuild
Yes those two are shorted. Here's my Q551 readings:
1-2: 100k
1-3: 54k
1-4: 52.5k
2-3: 47.3k
2-4: 46.8k
3-4: 543ohms <--interesting.Leave a comment:
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Re: Panasonic sc tnpa5081 rebuild
Q702 now removed, definitely bad... I am now seeing the 2.7k across the pads. Big 7805 checks out ok. I'm getting a lot of 47k to 52k readings across various pins of Q551. The surrounding R521 & R522 are right on the dot 100 ohms, D451 survived reading a good .488V drop. I'll post more findings later!Leave a comment:
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Re: Panasonic sc tnpa5081 rebuild
Unfortunately no scrap boards for parts, going to have to go shopping. This is my first attempt at a TV repair. I'm in no hurry though, already bought a new Panny S60... my brother will get the G25 if I can fix it. Looks like my buffer boards survived, getting a little over 2M on the VFOs & right at 219k on VCS-F.Leave a comment:
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Re: Panasonic sc tnpa5081 rebuild
I appreciate the reply. Good call on the inverter, removed from circuit and the 13ohms went away. In it's current state, I'm getting 5.6k on PV5... this is black probe on ground. If I switch probes it goes to 5.24k. PV15 is 2.66k black probe on ground, switched it becomes 1.55k. Takes a sec for readings on PV15 (caps charging?) Also, I'm getting a ~65 ohm reading on collector to emitter on Q702. I will check my buffer boards when I get home.Leave a comment:
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Re: Panasonic sc tnpa5081 rebuild
Hey guys, slight thread bump... this is the best source of info for this board that I was able to find. My TC-P54G25 just bit the dust, pretty much 3 years on the nose from when I bought it! Got the 10 blink code, so I disconnected the ribbon & power to the SC board and it went to 6. My first question is, is the damage usually isolated to the SC board or do the SD & SU boards get fried too? Thanks to this thread I was able to find some components that were bad. I'm an amateur when it comes to troubleshooting, I work with electronics as my...Leave a comment:
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