acer aspire m1641 no signal on monitor

A friend brought me their computer hoping I could fix it. No signal to the monitor. Tried new video card, did not help. Since Acer used a 250 watt power supply to run a 2ghz, 2 gig Ram, duo processor, I considered that perhaps the power supplied might be enough to run the led lights and the fan but not start the processor, so replaced power supply with a 450 watt supply and tried again, wouldnt even bring the lights or the fan on, returned that, got another 380watt power supply and put that in, the lights are on the fan is on and the dvd player shows lights and power getting to it, tried an auto start cd (music) in the cd rom and plugged in speakers, but sound did not start. and still no signal to the monitor. To insure power across the board, removed the memory and DID get the no memory beep code. replaced one stick of the memory and removed the battery, shorted out the jumper, started it without the battery in it, no beep codes, nothing to monitor, turned off, put brand NEW battery in turned back on, still nothing, monitor just blinks the amber light. Cannot access bios or cmos because no way to read screen that remains black. Any suggestions? Also cannot seem to find a schematic for this particular board anywhere online would appreciate any help offered