Just wondered if anyone had a good mainboard, TNPH0716AB or ABS, for a Panasonic plasma TV. Can't seem to find any online for less than $500, which needless to say is far more than the set (TH-50PX80U) is worth. I saw an eBay seller who was refurbishing these, but he refused to deal with me because I am outside the US (in Canada). I asked him for details on what was involved in refurbishing but he basically wouldn't give me the time of day. Thanks.
Have you ever found a source? I am Canadian too and having a lot of trouble locating one. Do you know what the difference is between TNPH0716AB and TNPH0716ABS. Thanks Matt
I have looked around and it looks like you might have to consider troublesh ooting this to component level. Are you familiar with the droppage of those 1117 regulators ? They seem pretty ubiquitous these days. They are a three terminal regulator available on a bunch of voltages and adjustable version (s). Surface mount and not all that big, they are probably quite on the edg e in dissipation.
I have access to one database still, and the problems for that set reported are the chopper in the PS shorted, and the main borad causing no video. Th ey said looking it it with the lights off you can see just a little bit of light on the screen but that's it. Is that your symptom ?
If this rebuilder can rebuild the board, what is he doing to it ? (is it Co ppel TV down in Texas by chance ?) thing to remember about a rebuilder is t ha tit is just as hard fro them to change a BGA chip as it is for anyone.
I can't get a picture of the ABS versiuon so I have no idea what the differ ence is. The rule of thumb here is that if you can see the difference it wi ll probably work, if they look identical it probably won't. If you're lucky it is more or less inputs or whatever.
Another thing to check is the EPROM. Somewhere near a big IC (the micro) th ere will be a small eight pin job. USUALLY after it's been plugged on for a minute or so, all the pins of that thing should be pretty much the same vo
, scope it. The pulses usually should stop after a while if no keys are pre ssed. If not, the data are probably FUBAR and the mocro keeps on polling it .
Unfortunately, the EPROM is usually good, it's just that something happened to the data. Things don't handshake. What rebuilders need in such cases is just ONE that works. they make the vconnections and copy the good data to a PC or whatever, and can reload the EPROM on the defective boards. They l ike that kind of job. The problem is getting the data. At one time they mus t have bought a working set, no matter what the cost because it is business . Now they want that money back from you.
In some cases you can get like a "firmware update" from the manufacturer. M itsubishi even lets the customer do that themselves with a USB stick drive. Not sure about Panasonic and I no longer have access there.
On the picture at Shopjimmy, I do not see anything that looks like an EPROM . It might be integral to the micro or something. It's also hard to see if it has a USB port, do you see one on the board ?
Hey, I got no direction to go at the moment, this is a fresh campaign. We n eed detailed symptoms, and you are going to have to try to identify the onb oard sources and all that.
See tose little coils there ? Most of them are chokes for switched mode reg ulators. That means that usualkly there should be voltage on them. Note tha t regulator ICs can look like damnear anything these days. Some don't even have a tab. At the top right is likely a class D audio output, make sure th at thing has Vcc and all that, that it is not shorted. Those things are a c ommon failure and then they take a source out with them. Rebuilders like th at kind of job as well.
Get them probes out. Maybe you can do nothing, maybe there is no way but to get a board, in which case Panasonic won. But you don't really know that y et.
If you can fix these with a ten buck IC, you won. It's worth a shot if you have basic electronics skills.
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