Originally Posted by
bigwerd360 
Hello. This is my first post here and from what I have seen, this is the best site when in need of PC help. I have 2 PC's that are not working and I cant figure out why. The first one is a PC I have had for a while and upgraded multiple times. I had a case that was broken, so i moved everything out and installed it into a new case. The only thing I changed was I switched my 7900GT out with an 8800GTS. I also changed the Heat sink and fan from an AMD stock one to an aftermarket one. After connecting everything, checking it, I plugged the PSU in and tried to start the pc, but nothing happened. The green light on the motherboard is on and the Ethernet cable is flashing orange, but the HDD, fans, etc. are not responding. I tried using the switch from my old case and nothing worked. I put my old graphics card in and my old heat sink in and still nothing.......
The second PC, which is one I am building for my wife, will turn on just fine, however it sends no signal to the monitor. I tried using the VGA on the motherboard and using the 7900GT DVI. Neither produce an image on my monitor and I dont know what to do.
Thank you guys a lot....you are a huge help and I am sure your guidance will help me through my PC tough times.
for the 1st problem check if the mother board is grounded properly. this means no circuit component is touching against the case.
Next verify that all jumpers are correct on the power panel Check the manual for correct orientation of the jumpers.
For the 2nd problem, Bow do you know the PC turns on correctly. can you use another monitor and get a signal or something on the screen? Remove the DVI card and work with the onboard VGA for now. if you are building and it board come with a VGA, and you install a DVI card there might be conflict with the IRQ. after you have gotten the monitor to work disable the onboard VGA throught the BIOS then put in the DVI card and then install drivers.