looking for panasonic upper buffer

[awyatt2]

hello all, find myself in need of an upper buffer that no one seems to have. tnpa4188 su of upper buffer board. it fits a th50px75u. heck of a nice tv if i can find the buffer. bottom half has a perfect pic upper half is black with startup glow. must be an open igbt the resistors, caps, diodes check good does not seen to have a fuse on it. anyone happen to have one in the spares box?

[tom66]

Re: looking for panasonic upper buffer

Startup glow on top half could actually indicate a bad D board...

[awyatt2]

Re: looking for panasonic upper buffer

tom, any ideas on how to determine without buying both boards? my luck runs bad and whichever one i get i will end up needing the other.
did you get the disc yet been about a week. don't know if it will get caught in customs or not.
i have a 150 meg tektronix scope, never used it much though mostly monitoring ripple in dc power supplys that i build. any input on this panasonic will be appricated greatly. i have a startup glow but no pic can see three distinct black lines in the top part bottom is perfect. i forgot and left the little plastic connector off and started it up and got three colored sections at the top and black lines were gone. these were blocks equally spaced across in a horiz. pattern and went halfway down. the upper buffer chips dont get warm at all the lower ones get warm but not to the point they would burn. that was what the assumption of sd board.

[tom66]

Re: looking for panasonic upper buffer

tom, any ideas on how to determine without buying both boards? my luck runs bad and whichever one i get i will end up needing the other.
did you get the disc yet been about a week. don't know if it will get caught in customs or not.

No sign of disc unfortunately. I'm keeping an eye out for it.

i have a 150 meg tektronix scope, never used it much though mostly monitoring ripple in dc power supplys that i build. any input on this panasonic will be appricated greatly. i have a startup glow but no pic can see three distinct black lines in the top part bottom is perfect. i forgot and left the little plastic connector off and started it up and got three colored sections at the top and black lines were gone. these were blocks equally spaced across in a horiz. pattern and went halfway down. the upper buffer chips dont get warm at all the lower ones get warm but not to the point they would burn. that was what the assumption of sd board.

The buffer boards just select the appropriate line to write to; you should see more or less the same waveform on each buffer output, same as Y-sus. You could probe the last output on each connector and see if you see a good Y-sus waveform.

[awyatt2]

Re: looking for panasonic upper buffer

good call Tom, saved me from looking for what i dont need it seems that it might be the d board, so now i am in search of a logic controller.

[tom66]

Re: looking for panasonic upper buffer

Can't guarantee it's the D board though, do the check I suggested.

[awyatt2]

Re: looking for panasonic upper buffer

i did tom, the signal on the top is out, but approx the same as in.bottom looks good both sides. top is not getting the signal in to go out. hope this makes sense to you no other way i know to explain it.

[tom66]

Re: looking for panasonic upper buffer

Sort of -- so you think D board?

[awyatt2]

Re: looking for panasonic upper buffer

i am gonna try it, hopefully it will get her running. nice tv i fixed an older panasonic a couple of weeks back for my daughter. this one is a friends set. he has a 62 i think he said that is working when it wants to if i can fix this one i can have the other one, which he is watching now.i cant remember if it was 62 or 65, it is a huge set though.

[awyatt2]

Re: looking for panasonic upper buffer

found a problem on the sc or ysus, two fets in series one has voltage in and out one has in no out. am going to the service manual now to see if i can find the sc board schematic.

[tom66]

Re: looking for panasonic upper buffer

http://www.tgohome.com/ServiceManual...&Search=Submit

[awyatt2]

Re: looking for panasonic upper buffer

looking like it may be the sc board i tried the d board and no improvment, the upper buffer was putting out basically what it was sent. some of these are a pain i guess. now i pull the sc and start trying to find the dead bird in the flock.

[tom66]

Re: looking for panasonic upper buffer

I doubt it's the SC. The SC sends the same signals to both boards. Any different signals are routed through the SC to SU/SD from D board.

[awyatt2]

Re: looking for panasonic upper buffer

upper buffer board, nothing else left. i figured it would be the last place i went. anyway i am still trying to source one. no luck not even ebay.tpna 4188.tried the d board and the sc board to no avail and both are known working boards.

[tw2005]

Re: looking for panasonic upper buffer

Maybe your filter is not set to worldwide?

All these in UK, this one is cheapest and maybe worth buying 2 or just in case you get sent a bad one. Cheap post as well.
http://www.ebay.com/itm/TNPA4188-1-S...item460c406ed7

Has 3, ships worldwide

http://www.ebay.com/itm/New-Panasoni...item20c9054327


http://www.ebay.com/itm/PANASONIC-TH...item460aceacb0

[awyatt2]

Re: looking for panasonic upper buffer

tw2005, most of the australia places wont ship to the us because of customs and paperwork. every place i have tried here is out. the local ones on ebay are far overpriced. so i will button it up and play the waiting game.

[tw2005]

Re: looking for panasonic upper buffer

tw2005, most of the australia places wont ship to the us because of customs and paperwork. every place i have tried here is out. the local ones on ebay are far overpriced. so i will button it up and play the waiting game.

All those were UK not Aust and ship worldwide as quoted in ebay. First link was the cheapest.

[awyatt2]

Re: looking for panasonic upper buffer

check the shipper info, when you try to get a quote they will tell you no shipping to usa.i know because i tried the reply was due to customs and holding times there was no shipping to us. guess they think tv parts are security risks.

i finally found one, replaced the upper buffer and bam! the tv came on full screen. just finished the job and picture is beautiful. may be replacing the samsung as i like the non glare screen. side tracked because of the avability of the buffer boards for this tv guess they are high failure.

[tw2005]

Re: looking for panasonic upper buffer

Most frustrating, I have the same issues at time finding stock but no ship to AU. Any excuse I guess, anyway you got one so well done.

At least SJ has ship in order, very professional.