Yes, the improvement is substantial, now i remember how good this TV set was good at first.
A reason more to be angry with Panasonic, the TV set that i used for years was well under its specifications.
I just made another important check :
sadly to say, SD card dump/recovery service feature does not affect panel clock EEPROM registers.
I made a SD dump just after panel clock reset and i applied it after some hours of TV usage, the panel clock was NOT restored.
Forget definitively the SD method for this purpose.
IF the first BL increase step is actually around 500 hours, in my case a "reset cure" would be necessary every 3 month.
There is people on http://www.hifi-forum.de/
that is modding the SC board (a trimmer plus fixed resistor in place of R607) for an additional BL step down, but at least in my case the risk not worth the plausible result.
High voltages are involved inside that boards (different P/N depending on TV model) and you have to deal with a small trimmer on live circuit.
If you are not a tech guy, stay far from that.
To summarize :
- with my TX-P50G10E (8000 hours) the I2C panel EEPROM (I2C addr : 0x50) clock reset works wonderfully, without the very difficult PCB via to GND connection
- black level dropped from 0.12 cd/m2 to 0.03 cd/m2
- SD card dump does not affect panel clock, so useless for this purpose