PC wont boot, just get black screen, but fans etc work?

If the card was on its way out, or the PSU? Well I asked the shop assistant, and he said it would be okay, as thos particular card, draws power from the motherboard and not the psu. It had no power supply. I mean I tested it out, and watched a few blu ray movies clips. Then, after changing my windows theme, it just went black(the screen), but power was still on.

So after I take the cmos battery out, do I leave the power plug out, or put the power plug back on? The battery is currently out, and I will leave out ALL night, and then replace in the morning, and switch back on, then report back.

Leave the plug out until you replace the battery.

Huwey said:

If the card was on its way out, or the PSU? Well I asked the shop assistant, and he said it would be okay, as thos particular card, draws power from the motherboard and not the psu. It had no power supply. I mean I tested it out, and watched a few blu ray movies clips. Then, after changing my windows theme, it just went black(the screen), but power was still on.

If the PSU was on its way out... And the card drawing power from the motherboard could still have overtaxed the PSU. The power in the motherboard has to come from the PSU, so the card is getting its power from the PSU indirectly. The PSU is still a possible source of your problems, but we will tackle that possibility after doing the BIOS reset via the battery removal and reseating.

I re-inserted the battery after leaving it out over night. I still get the "No video input" message on my monitor, however, it seems the internal sounds my comp used to make, when booting up when working, are now restored. It literally seems a case of there being no video sent to the monitor, i think the actual comp is starting up normally.

Another thing I have noticed, which seems like a big discovery, IS...

When I take take the VGA cable out the back of the comp, the monitor displays the message, "check cable connection". THEN as soon as I insert the vga, it says, "No Video Input" and goes into sleep mode. Surely it should be reset to using onboard graphics now, as I left the cmos battery out all night, but I dont know...It seems as though its still searching for the graphics card.

Anyone care to share there thoughts on this? Any help/advice?

Thankyou.

Your BIOS does not have an enable/disable feature for the onboard VGA, so it should always be on unless it was disabled through Windows, but even then, you should see something when the computer first turns on. The fact that before you were not getting the normal sounds suggests it is probably the PSU, but it may still be the motherboard. Only way to find out is borrow a PSU from a friend (at least 400 Watts, but preferably higher) or test your PSU using the method I linked to earlier.

Huwey said:

I also downloaded a reputable program called watt 2.2.5 to clear my windows non genuine message.

May I ask why you needed to clear this message? I hadn't noticed this until recently when it was pointed out by one of the other, more experienced users, and I would like to clear this up before proceeding further.

Ok, thanks for noticing that. Well the pc is pre-owned, and the previous owner had installed windows 7. It started comimg up with an ugly "non genuine" watermark on the desktop, and prohibited me from having a wallpaper. This program removed this.