Graphics problems

[redstern]

So this started happening recently.  Sometimes when I am playing a game at a random time, the game will freeze and the main screen will start strobing random colors, and either the game will crash after a few seconds, or I will have to restart my computer.  The strobing only happens on the main screen.  It happens randomly.  Today I was playing skyrim, and I was playing for 5 hours until that happened.  Then I restarted and it happened after 10 minutes, then I restarted and it happened after 3 seconds.  It will happen with pretty much any game.  I have a gtx 750ti.  The graphics card is overclocked, but I am using the same overclock that I have been using since I got the card ~1 year ago that has always been stable.  There also hasn't been any logged driver crashes.

[redstern]

I have tried lowering the overclock, results didn't change.  And yes I have a 6 pin power connected.  I will try lowering again once the problem happens agian.  Some days it doesn't happen at all.

[redstern]

It is a 600w.

[WhackingCheese]

Open up event viewer and check if there are any "Warning" or "Error" level events around the time of this happening, if you find something than post it here.

[redstern]

No nothing unusual in the event logs.  Also earlier I took my graphics card out, and took the cooler off to check the capacitors and other components, everything looks fine.

[redstern]

It seems that my card cant hold as high of an overclock as it could before. I turned down the overclock and so far it hasn't done that yet.