Troubleshooting with no spare parts

Hi, during some intense gaming my rig just BSOD out of nowhere, not knowing BSOD came with an error message I just powered it down. When I tried to boot it up it wouldn't turn on, so I popped open my case and started reseating hardware. This solved the problem, and now the computer boots

However when I connected my monitor to the graphics card I was getting no signal, and when I went to power down the pc by holding the power button down on my case it would not shut off, I had to flick the off switch on my PSU to power down the machine. On top of this I have literally no spare parts laying around to start troubleshooting, as this pc was my first build.

Specs are as follows
Tuniq Miniplant 950w PSU
2x2GB G.Skill RAM
Gigabyte Mobo, I forget the exact model, onboard sound.
Visiontek Radeon HD4870

My father insists it's a power supply problem, but to me it sounds more like motherboard or video card issues. Any help? :

Thanks for the quick reply, but no I do not have a case speaker so I cannot listen for the post beeps. I have regular speakers, will hooking those up to my mobo play the beeps? I have a Dell inspiron that I'm using right now, assuming my mobo does have onboard video would I be able to use that?

Also no, no audible discrepensies prior to the BSOD, but then again I had my headphones cranked up pretty loud so I can't really say for sure.

Yeah the case is wide open, and I didn't see any physical damage when I checked before, and all the smells are in order. Reset CMOS, but no dice. Another issue is my fans used to cycle when I turned on my PC, they started high and then went to medium, then to low once it started booting up. They don't do that anymore, they just start low and stay constant. I have... i'm not exactly shure of the name, but it's like the blue hookup to my monitor, but it's male to male, if you will, it's got pins instead of hole for the pins to be inserted into.

By the way, the piezo "case speaker" hunter315 recommends (I agree - check any computer parts shop) plugs into two pins on the mobo pinout set that also has connections to front panel on/off button, reset button, etc. Look at it and check for a label that tells you which pins.

Sounds like you have a VGA video cable, one of the most common types. It will have on both ends a connector with pins (that's a male connector) in three rows of five (15 pins total). The connector shell has a raised collar around the pins in a trapezoid shape - that is, almost a rectangle, but with one long side shorter than the opposite.

Just to check, when you reset the CMOS there are several steps you should have done: disconnect wall power, remove flat cell battery, short out the labeled pins for 5 sec or so, re-install battery, restore wall power. Then the last part is tough here - you are supposed to boot the computer and go immediately into the BIOS Setup screens by holding down the "Del" key, then use the menu choice to restore Default Settings or restore Optimal Settings. But that's impossible if you have no video display. Here's hoping it gives you something when you remove the video card and plug your cable into the back panel's VGA output connector. But you may already have tried this and not had any joy!

On your last question, you are right that either the mobo or the CPU could be at fault if the PSU replacement does not solve the problem. With no spare parts to work with, you might narrow this down with a friend's help. See if someone has a mobo that uses your same CPU. Can you arrange to remove your CPU AND heatsink/fan assembly from your machine and plug it into another machine to see if it works there? I recommend taking the CPU and the heatsink/fan together simply because sometimes the heatsink is tightly bonded to the CPU and it can be hard to separate them, clean off the thermal paste, then re-apply, etc. This may not be possible, though - on either your machine or your friend's the heatsink may prevent you from opening and closing the lever that locks the CPU into the ZIF socket. However, if you can do this, be aware that, when you plug the whole system into another mobo, the mechanical contact of heatsink to CPU may be poor and heat may build up rapidly in the CPU. So do not plan to run it long this way - only time enough to determine whether the system can get at least part way through the boot process and put a video signal up on the screen.