Resolved Monitors shutdown randomly

Hi all,
I'm having a lot of trouble with my computer monitors continually shutting down shortly after Windows bootup (getting 'no signal' from the graphics card). I have trialled with one monitor, as well as a different monitor (my TV), but the same issue recurs so I think I can safely rule out a faulty monitor.

This tends to happen whether I'm using Firefox/internet, or gaming etc, though I've noticed that when I load up a particular game (Second life, if it's relevant) it usually causes the symptoms almost immediately.
At first I thought this might be an adobe flash issue, or a graphics driver issue, or perhaps even a Firefox issue. I have run multiple scans, reinstalled drivers, booted in safe mode and done some troubleshooting, in fact everything I can possibly think of:

1) Ran CCleaner to clean temp files and erroneous registry entries
2) Completely removed Adobe flash player and Java (using Javara), and reinstalled, ensuring I used x64 bit compatibility for both programs
3) Ran Spybot and MSE with current definitions updates, and during safe mode
4) Reinstalled/updated all drivers, including motherboard/chipset and graphics card
5) Installed a x64 bit version of Firefox (Nightly) and disabled 'hardware acceleration' in Firefox advanced settings as suggested on some forum thread I found on the internet.
6) Reseated graphics card and sound card
7) Removed the soundcard, second HDD and DVD/CD drive (individually), rebooted, and tested - same problem each time
8) Restored BIOS defaults
9) Ran chkdsk, error-checking and defrag on primary HDD

I did read somewhere about adobe flash plugin for firefox casuing the issue, and the timing of this problem (approx 2 days ago) does oddly correlate with an adobe flash update that I allowed through Firefox - which is the only real change I can recall making in the past couple days.

I'm really at my wits end - can anybody help me figure this out?

Cheers.

Edit: Possibly relevant, 1 optional windows update continually fails to install successfully (Intel(R) Management Engine Interface)

 

My large screen TV/monitor is HDMI and I've tried it on that, with exactly the same issue as my two desktop monitors.

How would I go about determining a fauly PCIe slot or graphics card? Also, after using Speccy to determine my system specs I realised that some of them were running quite hot (eg 50C for the CPU), not sure if that's normal or not but could it be related to overheating? I also cleared out dust from the fans etc thinking that this might cause overall system instability, but it didn't help at all.

 

I went about switching the graphics card to the 4x slot as you suggested Pete, only to find that the site where the HDD SATA cables attach to the mobo block the edge of the graphics card, so I guess I can't test it in that slot.

As a side note, I've been moving my computer from one room to another for the past week or so - which also correlates approximately with when the problem started. My very first thought when I had these problems was that a cable had come loose (which has happened with my HDD SATA cable before), I've checked several times though to make sure everythings secure and it hasn't helped at all, unless I've missed something.

Also tried some other games, like Skyrim, and the monitor loses signal / switches off immediately.
I'd be a bit disappointed if this is a hardware issue, considering this computer is only 1 year old :/

Edit: Updated original post with points 6-9 (those things which I've attempted today).

 

I would swap in a known good power supply then see what happens. If you still lose signal, swap graphics card.

 

Eh, I haven't got a spare, compatible graphics card or power unit. I'm just going to have to take this in to a tech guy at this point, aren't I? I get the feeling I've done everything that can be done.

 

With no spare parts to test with, it does seem like you are running out of options.

 

I took my computer in to a tech guy today, will let you guys know what the problem ends up being,

 

Problem was with the graphics card! Replaced it for $125.
I'd be good to go except for the fact that he tried to 'repair' my windows installation for god knows what reason (even after I showed him everything I already tried and told him it was probably a hardware problem), and so he's broken Windows for me. Now I have to figure out how to repair it <sigh>. I suspect he tried to 'repair' it using x32 bit, when I'm on x64.

Anyway this can be marked resolved, and I'll work on repairing my windows installation now!

 

You mark your own thread as Resolved. Near the top right or these post, go to Thread Tools.