I would lean on the video card as a possible cause. Even though may have had good use until now, it has finally reached a point to give up. Alot is going on with the video card besides demanding a glob of power it also drives a "large video display". That scan rate and all it details becomes a huge task and on top of heat stress will find the weak link. Plus, you seemly your ad-hoc connection could also be an issue or it just adds to it all. In other words, you try to make this as clean as possible. The video card IMHO is stressed out(heat build-up) and one clue it blanks out but PC stills seems to be running. What you do after that is only going to compound into multiple problems, when the real issue is video alone. The simplest test is to swap out monitors or cards or both(test alone, separate) and do this on a long time frame. Alas, because you've had similar results with yet another PC also the problems arises after some time. What may seem like a simple task, is really a day in, day out hard one for the PC to maintain at whatever levels. Even if it falls within specs and can deliver it can't over the long haul, that's proven because this has happened on 2-PCs.
Fix: replace PSU with better wattage and another good known video card/source.
IMHO, your TV monitor maybe overall the crux of this situation. Check 100% the specs and clean-up connections. I find concoctions of sorts always tend to be hard to resolve because you have so much to wade through.
Hello, I've been having a problem with my computer the last week or so. My computer will be on and running fine, then all of a sudden my TV that I use as my monitor will go blank. The computer is still on, the fan lights etc are still on there's just no picture. Then I'll turn the computer off by holding in the power button then try to turn it back on. The computer will light up likes it's trying to turn on but I can hear that the computer isn't humming the way it usually does when it's on, and still no picture. Also, when it does that (turn on but not sounding as loud as normal) I can just touch the power button for a split second and it will power off, as oppose to usually having to hold the power button for a few seconds to power it off like normal. If I leave my computer off for about 5-6 hours it will usually turn back on and run for awhile again before repeating this cycle.
The TV I use as a monitor is a bit older, a 32' Toshiba Regza but it runs everything else just fine, like my consoles, laptop, bluray etc.. I have the PC connected to my tv via HDMI cord, but I use a rgb to hdmi converter to go from my videocard to the tv because I don't have a mini hdmi cord yet. My videocard is about a year old and its a nvidia gtx 560 Ti, so I don't think it's the card. My system is about 2 1/2 yrs old, it's a custom build from IBuyPower.
Thank you for looking and any help I can get I'd very much appreciate. I got this new IBuyPower because the Alienware I had before this was doing the exact same thing so I just sold it as is to help finance this one.