Here's what happens when I try to boot my PC: The fans spin, the HDD sounds normal, mobo light turns on, but monitor won't turn on.
At first I thought it was a problem with my monitor itself, but when I disconnect the VGA cable from the GPU, it shows the "No Signal" message. The moment I plug it back in, it goes blank and the power light (on the monitor) blinks steadily.
I tried connecting the VGA cable directly to the board but same output.
Then I thought it might be a problem with the RAM so I tried disconnecting one stick first, and booting. No beeps, fans spin, HDD sounds normal, mobo light's on, but monitor won't turn on.
Then I tried disconnecting both sticks. And, some-freaking-how, the same output! No beeps (no beeps!). Fans spin. HDD sounds normal. Mobo light turns on, but the monitor won't turn on.
What is going on here?
UPDATE 1: I just noticed the HDD activity light (on the front of the CPU) is not blinking when I try to turn the PC on. But, again, like I said, the HDD itself sounds normal. Spinning fine, no recurring clicks.
UPDATE 2: The PC turns itself off after a while; like maybe 15 seconds. I'm pretty sure this is a new symptom. Sometimes, it restarts itself, then switches back off another 15 or so seconds later. Sometimes, it stays off the first time. As of this moment, as I watch this happen, my RAM sticks are disconnected, my GPU is as well, and my monitor is plugged into the onboard graphics card. BIOS battery's in, BIOS jumper's in the right place (I'd tried clearing the BIOS earlier), and my HDD is connected.
Note: Still no beeping.
!!! UPDATE 3: I replaced the motherboard, and it started working !!!
Monitor's an LG
Board's an Intel DG31PR
CPU's an Intel i5 3337u
GPU's an ATI Radeon HD 4350
HDD's a regular Seagate 1TB
Please feel free to ask followup questions; I'm sure I've forgotten to include some detail or the other.
!!! UPDATE 3: I replaced the motherboard, and it started working !!!