Re: Panasonic TC-P65S1 mainboard

Just when I thought I had this thing fixed up...

Found out the TV's HDMI inputs, for whatever reason, will only accept input from a PC (laptop). When my HT receiver or Blu-Ray player are connected, I get no video.

What could cause this? Obviously the HDMI ports all work (electrically at least) since I get video from the laptop just fine.

Did I maybe create some sort of HDCP handshaking issue by swapping the CPU from another board? I'm not sure if there's anything built in the CPU that is unique to each...

Re: Panasonic TC-P65S1 mainboard

Well, the replacement board, TNPH0786 AJ suffix came in, after sitting for 4 weeks in customs

I swapped over the two EEPROMs that reside near the FPGA by the ribbon cables (they indeed had different data between the two boards). I put the board in the TV and... no good. Picture was overly bright and washed out. Thinking that maybe something in the software for the CPU had something to do with it, I swapped that over too. No difference. For good measure I also applied jumpers for the AM suffix, as expected, this did not make any...

Re: Panasonic TC-P65S1 mainboard

Well I've confirmed both through the schematics and scope measurements that the suffix jumpers are pretty much just a decoration. They don't connect to anything other than some test pads on the bottom of the board. I assume this allows automated testing equipment in the factory to quickly identify what version of board it's dealing with.



The dilemma is with the current board I have a TV that functions perfectly fine with 24Hz content (basically most any TV STB, DVD, Blu-Ray sources), so could still be a useful TV to...

Re: Panasonic TC-P65S1 mainboard



I kind of suspected that. Different panels likely need different timings to drive them properly.



So no need to swap the two larger EEPROMs (IC9303 and IC8502)?



Looks to me like the traces from those resistors/jumpers don't go anywhere other than some test points on the bottom of the board. Though it is possible it's connected to some traces on inner layers of the board through the vias. I'll have to measure these and see if there's any voltages appearing on the open jumper...

[B][U]Background:[/U][/B]

This TV has a weird fault where there is signal corruption on all the HDMI inputs, when running at 1080p 60Hz (which is a supported mode). I've tried many different cables and even different sources, with no difference. Running at lower resolution or refresh rate there is no problem at all.

The corruption presents itself as the signal occasionally going black, sometimes going all blocky, but sometimes is very subtle and presents itself as stray pixels flashing randomly on the image.

As the mainboard warms up, the corruption...

Re: New Members - please post your introductions here

Hello from northern Canada!

I've been tinkering with electronics since I was 8 years old, and currently have a job as an electronics technologist. I'm also an amateur radio operator and enjoy hiking, running, camping, cross-country skiing, and snowmobiling.

I don't like to take "not repairable" for an answer!

Looking forward to using these forums as another tool under my belt when encountering some challenging repairs (particularly consumer electronics, where detailed service manuals...