screen black without acces to the bios during start up

hello
first happy new year and sorry for my poor english

I have a acer 8204 travelmate with a big problem

during a connexion through modem all functions have been stopped with a black screen

since when I touch the power button the leds bright and nothing else the cpu cooler run for few secondes then nothing.
I suppose even the bios is not running .
i had disconnect the HDD, the memory the DVD burner and each time the same problem.

I would like to know where to find jumper or microswitch or wathever to reset the bios (hardware like a PC), I opened the 8204 dismantle the keyboard but I didn't find any jumper or microswith to do a hard reset.

so please if any knows how to find the way to reset the bios without any access (software), I'm ready to all proposals

thanks

gerard