Howdydo my fellow techies, I have a question for you regarding a strange problem I am experiencing recently on my PC and hope you can help me to solve it, or at least confirm what I suspect it might be. I've worked in IT and built/fixed many PC's down the years hence I would like to think I understand a bit about hardware and software, however what is happening is unlike anything I've come across before. So to the problem, I built this current machine back in October 09 and after about one month of everything running tickadeeboo I started to experience a 'No Video Input' message upon booting up. Immediately I thought bing!... graphics card failure. So opening up the machine I had a look at the card, fans were running so obviously some power getting to it. I powered down and felt the heatsink, it was warm so seems it had been operating to some extent. I unplug everything, pop the card out, reseat it, replace all connectors and switch on... powers up as normal, Sweet! So I use the pc, runs fine for several hours then I shut it down. Next day I go to boot my machine... 'No Video Input'. Hmm, power down, open pc, do same procedure as last time, go to boot but this time I get same message In the past I've had strange issues with ram modules causing a similar problem so I decide to take modules out one at a time and boot... same issue. Next I tried them in all different combinations, trying each stick in each slot... same issue. Next I decide 'ok could be the monitor', I try a known working monitor but same issue. Well hey it could be the fuse in the power cable, replace it and... same message. But maybe its the flex in the cable itself, try known working cable... comes on, Woot! Use as normal for several hours, switch off. Next time I go to use PC 'No Video Input'... Arrrgh! *slap forehead* Running out of ideas I start thinking the worst, it could be faulty graphics card, motherboard or PSU. Clutching at straws I flick off the power switch on PSU, leave to stand for about an hour, come back and switch on... Bing! It works After that occasion, several hours of use, power down, switch off. Only leave it for about 30 mins this time and come back out of curiosity, switch on... 'No Video Input', doh! Switch PSU off, come back one hour later... Woohoo! :grinthumb And so it goes, I begin to learn the nature of the beast, switch off PSU for about one hour and come back... guaranteed to work, lovely jubbly. Anything less and... 'No Video Input'. The key thing I have noticed in all this to give me a clue that it may be a PSU problem is that when it works the power supply sounds audibly louder during the initial 5 seconds bootup, but when I dont leave it off for up to an hour then it starts up noticably quieter, almost like it's lacking some oomph. So I'm hoping maybe one of you guys/gals may have come across something similar before. I can't find anything with google. Please let me know your thoughts.