Low +12V rail reading, comp shuts itself off during the night

[Ilias]

Hello to everyone. For the past week i have this problem and i am starting to wonder if my PSU (Enermax EG495AX-VE 485W) its the culprit. The +12V rail reading is pretty low in my opinion, 11.60V. Note however that this is a system that i work with all day and i never experienced any kind of problems, no reboots, no restarts, no freezes. Expect from two peculiar things:

1st is: Sometimes when i have to push the reset button on the case (happens to all of us i believe, one way or the other) the machine will stuck on the initial boot screen and wont go any further. The only way to remedy this, is to turn it off, pull out the PSU cable, wait a while, put it back in and then turn on the system again - with everything working properly and without a hitch.

2nd is: The computer i think turns itself off sometimes when i am not at home or sleeping (the machine is almost always turned on btw, doing some tasks). Happened twice this week. However when i am on the computer working or gaming, absolutely nothing wrong happens. Everything works like a charm.

I get the feeling that the PSU is the culprit behind all this - especially when i think of the low +12V rail reading (pic included below). Any opinions?

http://www.picoodle.com/view.php?srv=img02&img=/7/4/1/f_12Vreadingm_9576530.jpg

 

[Boonesmi]

im not saying your PSU isnt the problem... but 11.60v isnt "that" bad (personally i usually only run into problems when the rail's are more then 10% off... yours is only running about 4% low)

are you running the latest bios update?

 

[Ilias]

Hmm thank you for your input mate. No i dont have the latest BIOS update... had bad experiences with BIOS updates in the past and i don't want to end up with a bios-less motherboard :-/

 

[Boonesmi]

Originally posted by: Ilias
Hmm thank you for your input mate. No i dont have the latest BIOS update... had bad experiences with BIOS updates in the past and i don't want to end up with a bios-less motherboard :-/

i would really suggest you update the bios.. its a fairly safe procedure just make sure you read the direction carefully

 

[BonzaiDuck]

Because this thread interests me for the possible mis-diagnosis, I thought I'd start here and defer posting a "new topic."

Ilias says his PSU 12V rail is only showing 11.6V, and Boonesmi says that his experience with problems is confined to PSUs that are 10% out of spec.

I've planned this Core-2-Duo build since six months before the processor was released. I "politically engineered" the Christmas present of a Seasonic 650HT from a family member. The Seasonic box shows a voltage graph, noting that their supply is within +/- 3% of the voltage requirement. An article on a less powerful Seasonic S12 model at Tom's Hardware eventually leads to the conclusion that it is their "number-1 choice" among the 600-watt class. Their measurements show voltages for two of their Seasonic sample's 12V rails -- 11.87V, and 11.76V. The 3.3V rail also falls a tad short, as does the 5V rail. But the deviations for the 3.3 and 5V rails are lower than 2% off from the requirement.

My 12V rail measured in BIOS is a rock-steady 11.71V. I thought I saw some forum posts somewhere stating that the shipped BIOS version of my Striker motherboard is under-stating voltage readings. I thought I saw it -- I couldn't be sure. And most would say "don't just trust the BIOS readings -- use a multi-tester."

11.71V is still within Seasonic's promise for this unit. But what surprised me more, is that THG stated ATX specs as allowing +/- 5%. I had originally thought the relevant tolerance was +/- 2%.

Even so, the Striker project is off to a running start. Everything is working. Time to load the OS and drivers, then post my take on the Striker at the NewEgg User Reviews.

I just wish I could feel more confident about the Seasonic's 12V rails.