I have a custom-built system (not overclocked) I bought 1.5 years ago from CyberpowerPC. (Specs at end of post.) Up until about two weeks ago, it has functioned perfectly.
Recently it has been shutting down spontaneously - no warning, just instant off. Oddly, despite the BIOS being set to "stay off", it immediately powers back up. Most of the time, it comes right back up - Windows doesn't even try to go to safe mode. Sometimes this happens several times in rapid succession, and that DOES screw Windows up; occasionally I will also get beeps from the case: anywhere from 3-6 groups of three quick beeps. Once in a great while I will get a hard freeze (even had Pandora playing normally in the background once).
Things I have done:
Checked temperature, cleaned out dust, and run with case open - all of my sensors say it's not heat; nothing ever gets over 40C
Disconnected power and reset switches - no change
Pulled my video card and used onboard graphics - this caused a significant reduction in symptoms, but they still happen, usually right after I start taxing the system at all
Paper clip & multimeter on PSU - all rails show correct voltage, though I can't test it under load
MemTest86 - no errors detected
At this point, I'm pretty sure it's the CPU or motherboard; leaning towards MB because taking the video card out helped. (This actually made me suspect power for a long while, but that wouldn't explain the hard freezes.)
I don't have easy replacements for either. Any suggestions for an easy way to tell which one is the problem? (Or, for that matter, any other suggestions?)
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Specs:
Core i5-6500 3.2GHz
watercooling + extra case fans (overkill but it came with the system)
Gigabyte Z170 Gaming K3 motherboard
Lepa G1200 Gold PSU
Nvidia GTX 960 4GB video
2x 8GB ADATA DDR4-2800
SSD and spinner (both SATA III)
USB keyboard/mouse
doublewide monitor
Windows 10 Professional
Recently it has been shutting down spontaneously - no warning, just instant off. Oddly, despite the BIOS being set to "stay off", it immediately powers back up. Most of the time, it comes right back up - Windows doesn't even try to go to safe mode. Sometimes this happens several times in rapid succession, and that DOES screw Windows up; occasionally I will also get beeps from the case: anywhere from 3-6 groups of three quick beeps. Once in a great while I will get a hard freeze (even had Pandora playing normally in the background once).
Things I have done:
Checked temperature, cleaned out dust, and run with case open - all of my sensors say it's not heat; nothing ever gets over 40C
Disconnected power and reset switches - no change
Pulled my video card and used onboard graphics - this caused a significant reduction in symptoms, but they still happen, usually right after I start taxing the system at all
Paper clip & multimeter on PSU - all rails show correct voltage, though I can't test it under load
MemTest86 - no errors detected
At this point, I'm pretty sure it's the CPU or motherboard; leaning towards MB because taking the video card out helped. (This actually made me suspect power for a long while, but that wouldn't explain the hard freezes.)
I don't have easy replacements for either. Any suggestions for an easy way to tell which one is the problem? (Or, for that matter, any other suggestions?)
-----
Specs:
Core i5-6500 3.2GHz
watercooling + extra case fans (overkill but it came with the system)
Gigabyte Z170 Gaming K3 motherboard
Lepa G1200 Gold PSU
Nvidia GTX 960 4GB video
2x 8GB ADATA DDR4-2800
SSD and spinner (both SATA III)
USB keyboard/mouse
doublewide monitor
Windows 10 Professional
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