Second fried motherboard in three months. Bad PSU?

galingong

Honorable
Nov 5, 2012
19
0
10,510
Today my computer shut down without any warning, and haven't turned back on. No reaction to power button. I can start the PSU manually by shorting two wires. It has happened two months ago exactly like this. Back then I returned the motherboard to the shop, and bought an other one immediately (sorting out manufacturer warranty usually takes months here, I obviously needed a replacement to continue my job). I thought it was a simple motherboard failure. Now it turns out, that something else is also at fault. Can it be anything besides a failing PSU?

Both motherboards were Z97 (first one Gigabyte, second Asus), same CPU (4790k, base setting, no overclock). The PSU is an FSP Raider 750. Also the PSU seems to be correctly working (voltages are fine probing with a DVM). It was bought in 2013.

I also have to note, that today the PC turned off exactly when I turned an externally powered USB-hub on. The first time there was nothing power-related that I remember.

Any input appreciated. Thanks, cheers!
 

galingong

Honorable
Nov 5, 2012
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0
10,510


Damn...I was under the impression that this was a quality PSU, was not even cheap when I bought it. I'm trashing it right away. I'd be happy to receive tips on a new one.

My specs:
- Asus Z97-AR
- Intel i7 4790k (no manual OC, BIOS set to factory performance preset)
- G-Skill Ripjaws X 16GB DDR3 (2x8GB kit) 2133MHz
- Asus GTX670 DCUII 4GB
- May get a GTX970 or 1070 in the future, but planning to keep the 670 as well (could use both for rendering)
- 2 HDDs (7200RPM)
- Samsung 120GB SSD (830 AFAIK)
- Optical drive (DVD-RW)
- couple of USB devices (external audio interface, wacom, USB hub, card reader,
 

galingong

Honorable
Nov 5, 2012
19
0
10,510


Haha :DD Yeah, I'm aware that voltages drop and destabilize under load, I checked it to determine if PSU was also fried.
 
Well, EVGA and Seasonic make some of the best PSU's on the market. I would recommend one of theirs from tier 1 or 2 of the list I linked to. You would probably be fine with a 650w unit, unless you are thinking dual GPU's or SLI.

The new Corsair CX-XXXM series is pretty good as well, but make sure it's has the M in the name...the other CX's are the older line and were garbage.

I haven't made a specific recommendation as I don't know your budget.

If you upgrade, don't get the 970, there are far better options. Like a RX 580 or GTX 1060.
 

Petaflox

Prominent
Mar 30, 2017
28
1
530
Dry capacitor are a common problem in PSU even when is working, fast changing of load cause high sparks and if the capacitor are not efficient
there will be a damage.
Open the cover of your PSU and check the top side of the capacitor if are not flat or there is a brown stain ( very common problem ) then your PSU is
A MOBO killer.
After two losing two MB I wont trust the PSU anyway.
 


Defects are not always visible. You can be getting power surges and never see the issue. Especially because the defect didn't take the damage, the motherboard did.