I have a Compaq Presario that I acquired as a project computer.
When I received the computer, it was missing a hard drive, a case fan, and a power supply.
I subsequently installed a 300watt PSU, upgraded the RAM to 2GB, installed a 320GB SATA HDD, and installed a case fan.
I installed Ubuntu 12.04 on this computer and things seemed to be running great.
Recently, I would hit the power button, and the fans would start, but the monitor would indicate "no signal".
I removed the side panel and observed the system booting. The following describes what the system is doing:
Upon startup, the CPU fan will spin-up for approximately five seconds then stop, monitor will have no signal. However, the case fan will continue running. No system BIOS information will be displayed on the monitor. On rare occasions, if you leave the system running, the CPU fan will eventually start and the BIOS information will be displayed and Ubuntu will prompt for a login.
I've tried resetting the RAM modules --- no difference
I've tried a second 300watt PSU ---- made my monitor go crazy
Checked voltage on original PSU ----- 5v outputs reading 5.14v (rock steady)
Tried a new CPU fan --- shuts down after five seconds just like the original fan
Any help will be sincerely appreciated.