i have made a mistake last night : i have connected a power supply too high in voltage for the preenfm2 first run board.
Now i have a screen with few whites and black squares. Regulator 7805 was very hot. I have tested it and same voltage in input and output.
I have replaced it with a new one. Now i have 10 v in input and 5,2V at output.
But still strange screen with indications.
Where i can find reference voltage to check which components are out of service please ?
Thanks for your help.