Last Wednesday (5th December 2012) I switched my computer on in the morning to do some work on it. It failed to boot up. What I got instead was a black screen with a little box in the top left corner of both of my monitors (24" Samsung SyncMaster P2450 with HDMI connection & 22" Samsung SyncMaster 2033sw with a DVI connection) that kept flicking between 'Analogue, Digital & HDMI'. I'm not too sure how long it does this for, but it certainly goes on for about 5 minutes - I got bored timing it after then.

After some assistance from a friend, we figured out it was the Power Supply that went in the machine (was a CoolMaster 1000W Silent Pro). After replacing it with a Corsair GS850W Power Supply it had taken the GFX card (was a GTS 250 NVidia card) which has now been replaced with a GTX660 NVidia Card. This card has been in the machine for around an hour now and this little window is still popping up on Boot up.

It is doing my head in. I've changed ALL of the connections from the monitors to the tower, all the components inside the computer have been removed and placed back in one at a time and appear to be working - all the lights and fans turn on when I plug the machine in at least. I've spent the good part of a week trying to solve this problem on my own and I'm completely stumped. Any ideas?

If this little tidbit of information is useful, the PC was freezing up on me Tuesday evening. I installed Speedfan to see if the temperatures of the fans weren't ridiculously high and they weren't. They were running at a cool 60 degrees - even whilst gaming on Planetside 2 (which is what I was doing at the time).

Thanks in advance folks.

When you look in Device Manager, under Displays Adapters, what do you see?

From here you could try completely uninstalling your video card(s), and then install the latest drivers. (even if you feel you already have the latest video drivers) Be sure to download the drivers before your computer restarts so that they are available to install.

I can't actually get to the device manager to even look at it. The machine doesn't even get as far as the BIOS loading screen :(
A friend suggested that I test it with a different GFX card - which I did - same result occurred. I even plugged my monitor cables directly into the Motherboard and still no go.
I'm getting worried that whatever caused the Power Supply to go also took the Motherboard with it :(
Thanks for the response BigPaw


Ouch.... sorry to hear this.

There is just one last thing that might be worth trying, reset your BIOS. There are three ways to do this, but only two are available to you at the moment...

With power disconnected:

(a) Use your motherboard manual to locate the BIOS reset jumper. Or, (b) remove the CMOS battery temporarily and then reinsert it.

Hope it works matey.

BigPaw, thanks for the advice. Tried that and it still did the same thing. I bought a new Motherboard (Gigabyte 970A-DS3), fitted it in and the same problem occurs. Apart from the Harddrives, I've replaced EVERY SINGLE BIT of the PC (this was the plan after Xmas anyway) and the same problem is occuring. So currently the PC has;

Motherboard mentioned above
Corsair GS850 Power Supply
NVidia GeForce GTX 660
AMD FX 4100 CPU Black Edition

I assumed new components would be plugged in and would work instantly (after installing drivers etc but the screens still keep flicking between the different signal outputs...even when they are properly connected.

Any more advice folks.
Thanks again

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