Low voltage on the 12 v line affects?

[LSASr]

My systems runs stablily and I have a new PS coming. Just wondering how this low voltage is affecting my system if at all.

LSASr

 

[Ayah]

if it was the true, your computer wouldn't be running

 

[WobbleWobble]

I'll bet you're reading this from software, I would get out a multimeter and check again.

 

[LSASr]

Thanks for the replies.

I installed a new Enermax 600 Nosietaker (it was coming because the one it replaced was LOUD. Its readings are the same so it has to be a software board issue. Shows up in MBM and Sandra.

I'll just make sure its not below 10.7 from now on.

LSASR

 

[GalvanizedYankee]

LSASr, everyone who posts here as a rig builder should*invest*in a $15-$25 DMM (digital multi-meter).
PSU testers can be bought for $10-$20. I have a DDM and will buy a PSU tester with my next parts order.
Tooling is best bought before the emergency.


...Galvanized

 

[LSASr]

I have 2 digital voltmeters and a PS tester. I had never seen this behavior before and this was a new board. All the other voltages are correct so it was the anomaly of it being only the 12 volt line that threw me. Had i not had a new PS coming today I probably would have tested it but the question I ask is still valid. What actually runs on the 12 volt line. The drives are 5 volt and dimm and memory 1.5 and 2.0. I know their are 12 volts lines going to the MB. Is their anything else and what symptoms would be seen if, if any other than no boot, of course.

In this case both PSs showed 10.7 on the 12 volt rail and the new one is just that, right out of the box. I think I can safely and logically deduct that the voltage reading in the system is wrong. If I had not installed the new PS I would be doing just what you suggest but remember I did not change becasue of the 12 line i changed becasue the old PS was driving me out of my mind.

Now a question for you. I just went through several months of headaches due to another PS that tested fine but was reallying failing. The avaialble testers do not load the PS and under no load the one that failed was a champ. Is there any easy way to put a load on a PS in order to verify that it will actually work under load? I would find that to be a very valuable tool when trying to isolate issues with a PS.

Thanks

LSASr

 

[GalvanizedYankee]

I'll get back to you soon with links.

 

[Zepper]

Now that is not unusual for the -12V line as it is usually not loaded - but below a true +11V on the +12 is quite unusual. Fortunately almost all voltages that are taken from the +12 rail(s) are further regulated and filtered to a much lower value and the drives that use +12 directly are servo controlled and could likely compensate for a 1 volt or so drop. What is/are the Amp ratings of your current +12V rail(s)?

.bh.

 

[GalvanizedYankee]

http://takaman.jp/D/?english
This is not a current PSU calculator but will give a very good idea of what voltages are
used by differant hardware.
The newer hardware is power hungry for Amps@12V.(VGA & CPU)

http://www.pureoverclock.com/article15.html
Read the first five pages of this review. The first page is a little corny, but 2-5 offer solid info.

http://repairfaq.ece.drexel.edu/sam/smpsfaq.htm
Worth a look when you have time.

http://jonnyguru.blogspot.com/
Look this site over well. He will tell you what it takes to really loud test a PSU.
Be sure and look at all the links he offers that are of a tech nature.

http://www.motherboardrepair.com/
Yes, I know it says MB, but read the symptoms for bad caps. When PSUs have caps going bad the same symptoms will surface. The PITA about this condition is the the voltage will spike at boot killing HDs. The condition is intermittent so a DDM will not do. Opening the unit for inspection is the only option for the at home guy. Pics of bad caps at this site also.

One more. http://www.badcaps.net/

I'm just not throwing some sites at you. I've found/need imput from all six.


...Galvanized

 

[LSASr]

Enermax 701 Specs
5v rail 34amps
3.3v rail 34 amps
12v rail 1 18 amps
12v rail 2 18 amps
!2 volt both rails 35amps

everthing i read on this PS tells me those numbers are pretty accurate.

Yankee thanks for the links I'll read through them. I've not spent much time looking at PS issues until the last moth or so. Everytime somebody has a problem it seems the first response is change the PS. I don't think that's the panacea for MB problems but there is not much avaiable on how to test one properly so you're never really sure.

LSASr

 

[GalvanizedYankee]

Your EnerMax rates even with Seasonic for quality. VG units.
There are only two that rate better. PCP&C and Zippy/Emacs but they are expensive.
FSP Group, Fortron/Sparkle are the best bargain PSUs.

There is no way most of us can loud test a PSU at home.

...Galvanized

 

[LSASr]

Yankee;

Read thru most of those links.

Interesting that JohnnyG started out using lights to load. When i first started racing electric RC cars years ago we use to build light strips with 12v taillight bulbs (about 2 amp draw each) ususally 10 lights and test our nicads by fully charging them and then connect the lights and a vm and record the voltage drop down to about 5 volts on a 6 cell pack. Of cousre by the time i quit things where a lot more sophisiticated than that. I had two battery charger/testers by Victor and could push it down at 40 amps and record it on my laptop and a motor dyno that would give me hp, amp draw, torque, rpm, acceleration, etc. on my motors.

As a quick and dirty I might try using this same technique to load both the 12 and 5v rails. Even if you can't test them at their limits perhaps you could make a faulty PS show some problems by adding some load with enough lights.

Thanks again for the link. Think I'll look at the last 2 tomorrow.

So far the Enermax runs great. Picked it up in the FS board for $100. And it was really brand new all that was missing was the UPC lable from the box.

LSASr