[PSU] Is it my PSU?

Beryllium

Honorable
Oct 6, 2012
8
0
10,510
Hi there -

I've had intermittent hard shutdown problems (computer turns completely off, no reboot) for over a year and with money available have begun to narrow it down by switching in new parts, etc.

I've switched from a normal HDD to a SSD, Memtest'd the you-know-what out of my RAM, and experienced the shutdown with both onboard video and my current GPU (using both VGA and HDMI ports on each). I also just reinstalled Windows 7 for the sake of cleanliness, twice. All of my temperatures are fine, all of the time.

The only parts I have not changed at this point are the CPU and Motherboard. I just don't think it'd be a CPU issue for a full year running which leaves me with mobo and PSU. For as long as I've had this issue, I cannot remember if I switched my PSU for the sake of thinking I needed a "better" one or if this was done in response to the problem. Luckily I do have two for testing.

For the sake of not knowing, each PSU is labeled as potentially bad or potentially good. I just don't know yet ha.

My voltage values from the PSUs with HWMonitor and BIOS readings:

Potentially good unit (500W) cannot replicate shutdown with this unit:
HWMonitor - (12v)[11.88-12.03], (5v)[5.08-5.10], (3.3v)[3.33-3.34], (GPU's VIN0)[1.10]
BIOS - (12v)[12.03 constant], (5v)[5.082 constant], (3.3v)[3.327-3.342]

Potentially bad unit (650W) was installed for every known crash:
HWMonitor - (12v)[12.08], (5v)[5.04], (3.3v)[3.34-3.36], (GPU's VIN0)[0.90-1.10]
BIOS - (12v)[12.08], (5v)[5.042 constant], (3.3v)[3.342 constant]

So the biggest discrepancy between the two is the potentially bad unit hovers somewhat higher on the 12volt and varies back and forth between the GPU's VIN0 voltage from 0.90 to 1.10 while the good unit is locked on its GPU voltage. It is a PCIe card so it draws all the power from the board.

That being said, here are my current specs:
AMD Phenom II X6 2.8GHz
GSkill 2x2GB 1333 DDR3 kit
AMD HD6670 1GB
Crucial M4 64GB SSD

Any help would be greatly appreciated.

Thanks!

 
The fact that the 500W unit drops to 11.88 on the 12V rail would suggest it is suffering slightly under load, and the 650W looks quite healthy,so if the 500W has never failed I would be looking sideways at the mobo! Not sure about the VIN0, but would expect it would have an effect on the GPU rather than cause a shutdown...
 

Beryllium

Honorable
Oct 6, 2012
8
0
10,510
Thanks so much for your reply! I don't really have a lot of people to consult on this stuff so I really appreciate your input.

I do agree. Aside from a freak occurrence there is no longer another culprit and from the stories I've just now read about my particular model (M5A88-V EVO) it doesn't seem too uncommon for it to be a bad board. It's even discontinued on Newegg.com.

Hopefully they can get me a board of equal price that isn't my model.
 

Beryllium

Honorable
Oct 6, 2012
8
0
10,510
I will definitely take a look at that! I'm going to use a smaller board this time because it'll be cheaper for me to buy one now than to put the same model on hold.

Thanks so much for your help.
 

:eek:
From 12.03v to 11.88v
We don't know what psu it is
It's a software voltage reading, maybe not even taking load into account ( could just be idle readings )
If you trust software, and it is under load ( doubt it ) , ~1.3% voltage regulation is considered pretty good
12v+/- 5% or 11.4v - 12.6v is in spec, many more hardcore enthusiasts might retire a unit that's at 11.8, but it's really a non issue for 98% of computer users
One of the most reccomended budget grade power supplies never made it to 12v in normal load testing and shows similar regulation
http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story3&reid=239
 
I highly doubt it is the motherboard (the parts on a motherboard are so small and weak that if one fails even a bit, it normally takes the motherboard to the grave with it).
PSU is one of the most undervalued part on computer world when its actually your ENGINE if you compare it to a car.
Without your full PC spects (PSU model, and time its been running. Also does your electrical networt suffer from blackouts?) its hard however to know what component might be responsible, but as far as i know, if a PSU is very god quality, it basicly extends the life of every part of the PC, since it has a better contrl over the current that runs by your PC.
 

Beryllium

Honorable
Oct 6, 2012
8
0
10,510
I appreciate your point but one failure of the motherboard is simply not enough to take it down. It has too many parts. Plenty of ports available to short the board on accidental contact.

It's the next place to handle the power after the PSU so it can easily be an issue with voltage regulation on the mobo side, rather PSU. I'm using a pretty nice quality PSU and considering how stable it's running with its voltages (and paperclip test works fine) I'm leaning toward motherboard. It's the CPU that typically when something's wrong, the whole thing is likely a heartbeat away from going under. My CPU seems fine.

Frankly and unfortunately I think both PSUs are working.

For reference the 500W can't-remember-if-works PSU is a CoolerMaster Extreme while the 650W is the TX650W Corsair model.
 


Hi - Not 100% sure, but I believe the Coolermaster 500w is on 'Johnny Lucky's' lemon list. You can go to the top of the forum page and
go thru randomizer's 'Power Supply Guides' info post and research it. I pulled a Coolermaster 460w out of my PC after researching, and yes
it was on the lemon list as well.

Tom
 


Hi again - open the 1st link 'Computer Power Supplies - a Guide' and go to the bottom of the page, you should find 3 very useful links.

Tom