Hi, I have a DIY built desktop using a Gigabyte GA-X38-DS5 iX38 Socket 775 ATX Motherboard. I've just checked my records and this was purchased in 2008. Wow! I thought my rig was only about 5 years old, but it's actually just over 8 years old. SSD drives have definitely given it a new lease of life and it does just about everything I need!
Anyhow, back on subject. The build also includes a Gigabyte 8800GT 512MB GDDR3 Dual DVI HDCP HDTV out PCI-E Graphics Card and was powered by a 425W Hiper HPU4S435 PSU.
About 3 months ago, I started to have problems powering up the PC, but this could always be resolved by simply switching off and on the PSU switch. This then started to get worse and I would have to leave it switched off for 10 minutes before it would power up. It then got to the stage where I couldn't always guarantee I could get it to power up at all, which is when I purchased a new PSU as I had assumed this was the problem component.
The new PSU is a EVGA SuperNova P2 650 W Platinum Fully Modular. After booting into Windows 10 for the first time, I got a windows error after about 5 minutes, something about windows recovering from a graphics driver error, then the screen went black. This happened EVERY time I rebooted the PC, however, I noticed that I no longer needed to turn the PSU switch off and on, like with the previous PSU! Still, not much good to me if the screen goes black after 5 to 10 minutes!
After researching the issue, I booted into BIOS to check some settings and got distracted. When I eventually came back to the PC some 20 minutes later it had turned itself off and would not power back on. Nothing, no sign of life! I assumed the PSU had failed, so I swapped it out for the original "problematic" PSU and got the same - no sign off life.
I then disconnected the components and started attaching them one at a time. I found that the Gigabyte graphics card was causing the issue, regardless of which PSU I used.
So, I ordered a second hand replacement; a EVGA NVidia GeForce 8800 GTX 768mb GDDR3, which was a higher spec. than the original Gigabyte card. Unfortunately, on arrival I noticed it needed 2 x 6 pin power connectors, which only my new PSU could supply, so I've never been able to test this card with the old PSU.
Anyway, after fitting the new graphics card, the PC began to work again. So, it's possible the new EVGA PSU fried the graphics card OR that the card was on its way out anyway.
The strange thing is that although the PC works perfectly once it has booted, I still have the unusual starting issue. After powering down, if I don't flick the PSU switch off, then back on, it won't start and simply bleeps, powers off, starts up, bleeps, powers off, starts up - continuously, until I flick the PSU switch off. I've now got into the habit of flicking the switch off, then back on as soon as the PC shuts down, so I don't have an issue when starting up the next time.
I was able to borrow a VERY old WinFast PX6600 GT TDH 128mb card from a friend and tried this also, but get EXACTLY the same behavior, even when I use this old card with the old PSU.
So, it's seems like the common denominator is the motherboard as I've now tried two PSU's and two graphics cards.
Does this sound like the kind of fault that could be caused by my Gigabyte motherboard?
Sorry for the long post, but wanted to give you the full picture of the issue.
Thanks in advance.