Hello @ all,
recently I purchased an used TX-P50U30E because of I love the color and contrasts of Plasma TVs. At the same day of purchase, in the evening I was really unsatisfied because of the grey black
After many research I found out about the rising MLL in newer Panas. So I read and understood all. My Plasma has round about 4600 hour on-time and 2200 On/off cycles. It is made in 2011. After many research I found panasonic.mironto.sk which explains how to rewrite eeprom in older models to restore black but I think no one has done it with my model?!?
So I started to "work" and I got in contact with miro.
I ordered an arduino uno (compatible)
I built a 14-pin connector using an old DDR-Module's contact (I attached a photo of the serviceconnector with my plug inside. I know - it does not seem to be professional but it works. Everytime I plug it in I measure with an ohmmeter, it every time has contact and there are no shorts!!!)
In my "unknowness" I connected pin 3 and 10 to gnd, disabled internal pullup of arduino, uploaded miro's code connected pin 8 and 9 to SDA and SCL of the arduino. First all seems to be okay, the TV switched on, the panel stayed blank (as it should be, when Pin 10 -> GND). But my arduino did not read something. Miro told me, after sending him the service manual to use pin 12 or 11 instead of pin 10. But with 11 or 12 connected to GND the TV boots up normally, Panel switches on and reading with arduino is also impossible.
To test I took an old SD-RAM and connected the SPD eeprom to my arduino and it also reads out nothing
. The conclusion: the adruino seems to be defective (this is my normal luck)
To verify this I read in how to make I2C eeprom with raspberry (I have one lying unused here around).
I downloaded and installed Raspi from 2/2015
activated I2C in raspi config (thats new since Raspi version from 2015)
activated the loading of the modules for I2C
downloaded some i2c tools and EEPROM reader and writer for linux
connected the spd eeprom to raspberry and: all works fine. Raspberry found SPD module at 0x50
I can read and write every one of the 256 bytes provided by the spd module.
So I gave it a new try:
connected the Raspberry to 3(gnd) 8 and 9 (SDA and SCL) and tested pin 10 to GND, pin 11 to GND and pin 12 to GND. But with no one of the constellations it was possible to read (or find) the panel's eeprom. There is a tool called i2cdetect. Sometimes, when TV booted up normally it randomly finds some??? eeproms with random IDs but I think (and it must be) it is an interference between the raspberry and the normal TV internal traffic between it's I2C master and the panel's eeprom....
Every step I made I stood in contact with miro (Thank you for all your help and time spended in reading and writing emails) but now we are at the point to get further help, he advised me to tell my problem here in this forum....
I attached a screenshot I made from the Servicemanual's SWF file. There you can see the 14 pin serviceconnector. For me, the pin 12 seems to be N/C and I measured an infinity resistance against ground. Pin 11 seems to be shared but it does not work when I connect it to gnd (3), TV boots up normally.
I think I am not far away from the solution to get access to the eeprom but there seems to be one little thing to solve...
If there is any information I should provide, please let me know, I'll do all to help others and myself to restore the real black on the TX-P50U30E (and similar models)...
Thank you in advance