System Powers on then nothing

[li0nhart79]

About a week ago I did a fresh resinstall of Win7 on my mom's PC to attempt to correct some USB detection issues and it worked great. System seemed to run even better after the install. Just tonight my mom let me know that the monitor would not turn on. The light was yellow instead of the normal green. Yellow is what it stays when the computer is asleep. Powering off then on didn't correct the issue so I checked the monitor cable....nothing. I swapped from the GPU to the onboard VGA and still nothing. I tried an extra monitor just to troubleshoot the monitor itself. The spare actually popped up a box the said "warning PC entering power saver mode" No BIOS screen or any of the normal boot menus appear. Everything powers on and runs but nothing going to the monitor. I reset my CMOS as well and nothing. The mobo has the lil speaker hooked up for boot messages and it's not beeping at all but to be honest I cannot recall if it ever did as the CPU is under a desk out of earshot to hear much from it.
This is a new issue for me so any advise would be awesome. Oh I also just the other day removed the CPU cooler to clean out the heatsink. It was so gunked up I didn't want to blow it out inside the tower so I removed it and reapplied a fresh dab of arctic silver.

 

[o1die]

Pull the motherboard battery off for one minute with the power supply unplugged in case resetting the cmos jumper didn't take. This will reset the bios for sure. And if you're trying to use sleep or hybernate mode, I no longer recommend it. If the board posts but stops at the post screen, disconnect the hardrive and try each ram stick one at a time as part of a troubleshooting routine.

 

[li0nhart79]

Best answer selected by li0nhart79.

 

[li0nhart79]

Thanks! I had only tried the jumper not the battery. Removing the battery and resetting the CMOS jumper worked. I also did as you recommended and turned off the sleep mode option.