T43 2668 blank screen on power-on

[Lean]

Hello,
My T43 /2668 remains with black screen after pressing the power button. Leds are lighted and the fan starts blowing noisily.
I was told that it could be a motherboard fault, located at H8S2161 I/O Embedded Controller.
Could I insert a boot-block jumper (update key) on LPT port and place a diskette containing the Embedded Controller Program (1yhj06ud.exe) to fix a possible I/O EC fault?
Any suggestion about how to fix this issue is wellcome!