Panasonic plasma TH-42PZ80U or TH-42PZ80UA, 7 blinks, random green image, questions
I am not DIY enough at the moment to deal with testing for voltages with multimeters, recapping/soldering, and such. If it’s really not hard to do, though, I suppose I can go out and buy one. There is a repairman 60 miles away so I can take it to him but I need to know some things to decide if it’s worth putting a bunch of money and time into.
Before the TV refused to turn on with the 7 blinks the picture would randomly turn green or partially green once in a while. Not a “green screen” but television images only with just the color green, or mostly just the color green. This happened over a period of a month or two. It was rather random. Most of the time everything would be fine and it would clear up, too. However, sometimes it wouldn’t clear up so I’d turn it off to let it cool down. I think there may have been horizontal banding (like scan lines) happening in the images that were shown as well.
I do not remember hearing any popping sound or smelling anything. If there was a pop I’ve forgotten about it. I am completely sure I didn’t smell anything burning.
1) I’ve heard that it’s a “known issue” (design flaw) that wasn’t fixed. In a later model(s) there was a screw kit released to fix the problems with those. Apparently, it was that there wasn’t enough pressure which caused arcing. Is that the cause of the SC failure apparently being common for my set as well? If not, why is SC failure common and is it something I can do something about, like jury-rigging extra cooling?
2) Everyone selling the used parts claims they were pulled from sets that had damaged panels (except for one listing that actually said they were pulled from a TV that wouldn’t turn on), usually from shipping. I’ve already read one person who ended up buying dead replacement boards. Any suggestions? The feedback score of the people I’ve seen listing parts on Ebay has been really good so it makes me wonder how they could sell bad boards. I suppose I should stick with vendors that allow returns.
3) I didn’t see anything wrong with the boards. The only question marks are the amount of dust that was inside the TV (a lot — all cleaned out now) and rust/corrosion spots on the bottom of the case. I thought maybe those could be from dripping capacitor liquid, if it’s anything like battery acid. But, no caps appear to be bulging. I didn’t see any staining on the boards. I took the SC board out and the back looks fine. The SU and SD boards also look fine. The ribbon cables look good and were very snug. The only oddities I saw were snail-like light trails on the bottom of the board in three places, like scratches but the surface was smooth. What are these?
4) A repairman said that a lot of these TVs had problems with the boards going bad and Panasonic had to replace so many boards that the repair program was ended due to costs, or something like this. He also said that if the SC board is okay and either the SD or SU boards are bad there is a strong likelihood that if one or both of those boards are replaced it will short the TV, causing more damage (like frying the SC board). I’ve also read that if a person uses a bad SC board it can fry the SD and SU boards. So, my idea was to replace all three at the same time but I’m concerned about that plan due to what he said about how it’s common to short out the TV when trying to replace the SD and SU boards. Is this because of all the ribbon cables? I’ve read that it’s difficult to get all of the ribbon cables seated well.
5) Someone said they would use solder in screw holes to prevent the arcing problem. Is something like this needed for this model or just the TC-P50GT30 or some other model?
6) The TV only has three fans but four places for fans. Would adding a fourth fan help with longevity or do I need to get a very thin fan and jury rig it somehow so it can cool the SC board more? It looks like there is room below the SC board to put a fan in but how to power it and how to secure it… Is there a way to improve the heatsink situation on the SC board?
7) Can dust alone cause the green screen issue and/or the 7 lights? It was very full of dust on the inside, even though I had kept the outside clean. Panasonic’s manual should have told people to take apart the TV every so often and clean it.
8) Is a loose ribbon cable really a possible cause of my issues? Everything points to the SC board but I want to make sure I’m leaving no simple stone unturned.
9) Is the green images issue separate from the 7 lights issue, such as a problem with the power board? Why would the TV continue to work normally most of the time with this green images problem? Is it because a capacitor was only partially bad? Is it because something was delivering marginal voltages? Is it just because of dust overheating? Is whatever it is dead or is it possible that I could reassemble the TV and find it working?
10) The repairman said I could unscrew the SD and SU boards, take off the ribbon cable connecting them to the SC board, and make sure they’re not touching anything. Then, I could turn the TV on. He said that if the TV shuts down that’s the SC board being bad and if it doesn’t it’s one or both of the other boards being bad. He said that if it’s one or both of the other boards it’s probably not worth trying to replace them because of the likelihood of shorting out the TV. Is this correct? Is there something relatively simple I could to do prevent that from happening?
11) My TV is very confusing to identify. It has a silver sticker on the back that says the model is TH-42PZ80UA but there is a white sticker by it that says it’s a TH-42PZ80U. The sticker on the inside of the case says mc106f16t11. So, not only am I unsure about which TV I actually have, all the board replacement vendors warn to order by part number not by board number. Well, I looked on both sides of the boards (like SC) and didn’t see any part number. All I saw was the board number. In the case of the SC board it’s TNPA5657 AC 1SC. Listings I’ve seen show parts for TNPA5657AC but that’s the board number not the mysterious part number. Panasonic seems really intent on making this as difficult as possible for someone who’s not a pro.
Sorry about the length of this message but any help is appreciated. I would just replace the TV but I can’t find anything for a reasonable price that has good viewing angles and good contrast. I don’t have the funds for OLED.
All the same, if this TV is anything like the expensive GE (piece of junk) fridge that I poured a huge amount of money in (three or four boards replaced and it still had to be thrown out) then I don’t want to go through that. The fridge was top-rated by Consumer Reports and had exposed liquid caps. Smart… Our Kenmore dishwasher also had liquid caps on its board that failed. So did our microwave. So did our range. The Maytag repairman said it’s a “known issue” with the model I have and that the later model didn’t have the problem. LOL. Our GE dryer also failed shortly out of warranty. Not sure why it died out of the blue, other than being a GE product.
I also found this post. It’s not the same model (the thread is for TH-42PZ77U) but I wonder if there is a similar issue with mine:
But there is also this success story with a different model:
referring to the TC-P50GT30
I'm curious about these procedures. Are they applicable to my set? What about just putting a fourth fan into it at the top right? Too far away to make a difference?
Before the TV refused to turn on with the 7 blinks the picture would randomly turn green or partially green once in a while. Not a “green screen” but television images only with just the color green, or mostly just the color green. This happened over a period of a month or two. It was rather random. Most of the time everything would be fine and it would clear up, too. However, sometimes it wouldn’t clear up so I’d turn it off to let it cool down. I think there may have been horizontal banding (like scan lines) happening in the images that were shown as well.
I do not remember hearing any popping sound or smelling anything. If there was a pop I’ve forgotten about it. I am completely sure I didn’t smell anything burning.
1) I’ve heard that it’s a “known issue” (design flaw) that wasn’t fixed. In a later model(s) there was a screw kit released to fix the problems with those. Apparently, it was that there wasn’t enough pressure which caused arcing. Is that the cause of the SC failure apparently being common for my set as well? If not, why is SC failure common and is it something I can do something about, like jury-rigging extra cooling?
2) Everyone selling the used parts claims they were pulled from sets that had damaged panels (except for one listing that actually said they were pulled from a TV that wouldn’t turn on), usually from shipping. I’ve already read one person who ended up buying dead replacement boards. Any suggestions? The feedback score of the people I’ve seen listing parts on Ebay has been really good so it makes me wonder how they could sell bad boards. I suppose I should stick with vendors that allow returns.
3) I didn’t see anything wrong with the boards. The only question marks are the amount of dust that was inside the TV (a lot — all cleaned out now) and rust/corrosion spots on the bottom of the case. I thought maybe those could be from dripping capacitor liquid, if it’s anything like battery acid. But, no caps appear to be bulging. I didn’t see any staining on the boards. I took the SC board out and the back looks fine. The SU and SD boards also look fine. The ribbon cables look good and were very snug. The only oddities I saw were snail-like light trails on the bottom of the board in three places, like scratches but the surface was smooth. What are these?
4) A repairman said that a lot of these TVs had problems with the boards going bad and Panasonic had to replace so many boards that the repair program was ended due to costs, or something like this. He also said that if the SC board is okay and either the SD or SU boards are bad there is a strong likelihood that if one or both of those boards are replaced it will short the TV, causing more damage (like frying the SC board). I’ve also read that if a person uses a bad SC board it can fry the SD and SU boards. So, my idea was to replace all three at the same time but I’m concerned about that plan due to what he said about how it’s common to short out the TV when trying to replace the SD and SU boards. Is this because of all the ribbon cables? I’ve read that it’s difficult to get all of the ribbon cables seated well.
5) Someone said they would use solder in screw holes to prevent the arcing problem. Is something like this needed for this model or just the TC-P50GT30 or some other model?
6) The TV only has three fans but four places for fans. Would adding a fourth fan help with longevity or do I need to get a very thin fan and jury rig it somehow so it can cool the SC board more? It looks like there is room below the SC board to put a fan in but how to power it and how to secure it… Is there a way to improve the heatsink situation on the SC board?
7) Can dust alone cause the green screen issue and/or the 7 lights? It was very full of dust on the inside, even though I had kept the outside clean. Panasonic’s manual should have told people to take apart the TV every so often and clean it.
8) Is a loose ribbon cable really a possible cause of my issues? Everything points to the SC board but I want to make sure I’m leaving no simple stone unturned.
9) Is the green images issue separate from the 7 lights issue, such as a problem with the power board? Why would the TV continue to work normally most of the time with this green images problem? Is it because a capacitor was only partially bad? Is it because something was delivering marginal voltages? Is it just because of dust overheating? Is whatever it is dead or is it possible that I could reassemble the TV and find it working?
10) The repairman said I could unscrew the SD and SU boards, take off the ribbon cable connecting them to the SC board, and make sure they’re not touching anything. Then, I could turn the TV on. He said that if the TV shuts down that’s the SC board being bad and if it doesn’t it’s one or both of the other boards being bad. He said that if it’s one or both of the other boards it’s probably not worth trying to replace them because of the likelihood of shorting out the TV. Is this correct? Is there something relatively simple I could to do prevent that from happening?
11) My TV is very confusing to identify. It has a silver sticker on the back that says the model is TH-42PZ80UA but there is a white sticker by it that says it’s a TH-42PZ80U. The sticker on the inside of the case says mc106f16t11. So, not only am I unsure about which TV I actually have, all the board replacement vendors warn to order by part number not by board number. Well, I looked on both sides of the boards (like SC) and didn’t see any part number. All I saw was the board number. In the case of the SC board it’s TNPA5657 AC 1SC. Listings I’ve seen show parts for TNPA5657AC but that’s the board number not the mysterious part number. Panasonic seems really intent on making this as difficult as possible for someone who’s not a pro.
Sorry about the length of this message but any help is appreciated. I would just replace the TV but I can’t find anything for a reasonable price that has good viewing angles and good contrast. I don’t have the funds for OLED.
All the same, if this TV is anything like the expensive GE (piece of junk) fridge that I poured a huge amount of money in (three or four boards replaced and it still had to be thrown out) then I don’t want to go through that. The fridge was top-rated by Consumer Reports and had exposed liquid caps. Smart… Our Kenmore dishwasher also had liquid caps on its board that failed. So did our microwave. So did our range. The Maytag repairman said it’s a “known issue” with the model I have and that the later model didn’t have the problem. LOL. Our GE dryer also failed shortly out of warranty. Not sure why it died out of the blue, other than being a GE product.
I also found this post. It’s not the same model (the thread is for TH-42PZ77U) but I wonder if there is a similar issue with mine:
But there is also this success story with a different model:
1. Replaced the bad 6 transistors with the new one.
2. Install the board back to TV, but NOT connect to the buffer boards (SD/SU) (I even disconnected the grounds, no physically touch between the SC and the two buffer boards).
3. Shorted the SC50 (I used an old IDE hard drive jumper)
4. Plug and Turned on the TV, it powered up constantly, no blinks any more, TV response to the remote control.
5. Unplug the power cord from the wall, wait for 5 minutes.
6. Connected the SC board with the SU/SD board firmly (connectors and grounds).
7. Plug and turned on the power supply, TV lite up ! Everything works !
2. Install the board back to TV, but NOT connect to the buffer boards (SD/SU) (I even disconnected the grounds, no physically touch between the SC and the two buffer boards).
3. Shorted the SC50 (I used an old IDE hard drive jumper)
4. Plug and Turned on the TV, it powered up constantly, no blinks any more, TV response to the remote control.
5. Unplug the power cord from the wall, wait for 5 minutes.
6. Connected the SC board with the SU/SD board firmly (connectors and grounds).
7. Plug and turned on the power supply, TV lite up ! Everything works !
I'm curious about these procedures. Are they applicable to my set? What about just putting a fourth fan into it at the top right? Too far away to make a difference?
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