Many questions about power supplies

[Foxie3a]

Alright, I have an FSP400, so it's time to open her up and adjust the pots.

My 12V rail under loads goes down to 11.5-11.6v which is not acceptable for me at all. I've been doing a lot of reading and it looks like most of the juice comes from the 12V rail, that and the 5v which is just fine on mine. It stays at 5.13v most of the time, lowest it's ever gone is 5.07 or so.

The max my 12v has ever been is around 11.9 and average is 11.8. So I figure I'll bump it up atleast 0.2v. I'm thinking more. How high can I safely go? Would 12.2v be safe to have it at normally since under load it'd go down to 12v? I think that it'd be safe, and I plan on doing that unless if anyone objects.

Now for pots. I havn't openned this PSU, and I've never seen a pot. Does anyone have pictures? Does anyone know which is which off hand in the sparkle 400? I figure I'll sit in my BIOS and watch the voltages and slowly adjust them. I can do this with a screwdriver I'm told, correct? Does anyone have any suggestions when I do this?

I'm also thinking of getting a new cover for the PSU that has a 120mm fan hole on it to help cool it. Currently it just has one exhaust, 80mm on it blowing out the back. The extra fan would just be for fun, but maybe it'll actually do good.

Alright, can you guys help answer those questions for me?

I posted this on OCF, but no one feels like reading any threads created by me over there, or they dont know how to reply. I really need some advice XStreme!

[Flib]

12V rail would be 100% safe at 12,6V that's a 5% increase

Have you measured with a DMM or are the readings from the bios?

[Foxie3a]

Mostly I read from MBM5. I have read with my multimeter and the voltages were reading the same. I havn't sat there with it for hours to make sure though, but for a minute they were reading the same, including peaks. I would adjust the pots using a multi meter and my bios. I already know my averages/peaks for each rail after about 12 hours of both idle and full load.

I have my questions answered for now. I dont feel safe with a 12.6v rail though. I'm going to put it upto 12.2, maybe 12.25, somewhere around there.

Oh, does anyone know where I can get another cover for my PSU? One that has a fan hole in it?

[STEvil]

Use your multimeter when adjusting it.

As to a new cover, I dont think you can buy new ones retail. If you bought a cheap PSU and swapped the internals between them they should be fine, just be carefull because touching parts of the internals of the PSU can be dangerous to your health!

[Kobalt]

svc.com
xoxide.com
sidewindercomputers

google around, but i personally prefer svc...cheap fast reliable and no bs!

things that will happen with the increase of the 12v rail are... any devices that draw power from the 12v rail will be able to use more current, and your fans will spin faster as well as your hard drives.

here are some with a 92mm hole...i dont know of any with a 120mm hole though

http://www.svcompucycle.com/posumodw92ho1.html

[STEvil]

Current limitation is due to wire guage and amperage supply of the PSU, not voltage.

[Foxie3a]

My 12v rail has a low peak of 12.5, a high peak of 11.92, and an average of 11.8.

This is all from MBM5 which I feel is reliable.

It goes down to 11.55 or so under a strong load. I got the 12.49 peak using Prime95, audio encoding, and Sandra benching at the same time.

It rarely even peaks at 11.9, it's usually at 11.8 or it'll go a little lower. I'm thinking 12.3v is what I'll set it at to compensate for it's low peaks, give it a lot more juice, and not too high because of it's ~0.1v+ peaks.

Do you think that would be bad for my hard drives? One is a raptor, the other is a 250gb maxtor. Both were made this year, so I'd think they'd be able to better withstand more voltage.

[Kobalt]

everything will be fine.

[STEvil]

low peak of 12.5, high peak of 11.92, average 11.8... how does that work?

MBM5 is only as reliable as the sensor chips on the motherboard, since that is what it uses to report its numbers.. I dont trust them one bit.

[Flib]

readings are different from motherboard to motherboard,
a new psu won't change the readings, they will be nearly the same.
(only when your psu really sucks they could change)

What did your DMM say?

[Foxie3a]

Multi meter agrees with MBM5 in the short tests that I did.

"How does that work?" It's just what MBM5 is telling me. I am beleiving MBM5/my mobo since my multi meter agrees. If they're wrong, it's my fault, but that's why I'm here. :)

I have an IC7, are those known to have anything weird about the voltage readings? I have the latest BIOS, and I saw they "calibrated" the temp sensors, but I didn't see any change between BIOSes.

[STEvil]

Typically low is the lowest recorded, high is the highest, and average is the average results of all the recorded results (will be between low and high therefor)...

Your results should be low of 11.8, high of 12.5, and average 11.92 according to the numbers you gave....

[Foxie3a]

I meant to say a low peak of 11.5, not 12.5

I opened up my PSU tonight! It was pretty easy to find the pots, they were right on the top staring at me as I opened it. Only two though. I figured 12v and 5v.

I memorized where they were, and tried moving them, they wouldn't move, then suddenly it moved and made a cracking noise, I was scared until I remembered the goop they put on them, and I looked and saw I broke the goop to hold it in place.

Then I put them back to where they were, and turned on my computer. I figured I'd use MBM5 with my MM for it, so I loaded into Windows. I ran MBM5 and got SOO scared when I saw the voltages. I apparently didn't put them back to where they were.

I was at 12.6 and 5.3v. So I tried putting one down, but couldn't figure out which rail it was effecting because both my 12 and 5v went down at the same time.

After a few minutes of being scared to death of my high voltages I figured out that the 12 and 5v share the same pot. I didn't think they could do that, but that's the way it is. Since my 5v was rock solid at 5.1v and my 12v wasn't too good at around 11.8, I couldn't bring it up too much.

Average now is 11.9 and 5.2v. A lot better than before. The peak for the 12 is 12.1, and a low of 11.73, and I havn't gone into load yet, but I figure it'll still drop down pretty far. I really wish I could have left the 5v where it was and just cranked up the 12v. :(

The other pot was the 3.3v. That is now running at 3.4v average. With peaks of 3.8 and 4.3.

I havn't tried OCing since this, and these numbers are all pretty much during idling. I'm just saying what I've experienced.

It's definately scary doing this, especially when you dont know which pot is for which rail. If I had to do it again, I'm not sure if I would. Maybe I'll reply back here tomorrow and try to OC, see if I can go any higher than I can now, but I doubt it, I didn't get my 12V up high enough, and my RAM can't do anymore than what it's doing anyway.

[zA.Gosu]

Well, maybe that'll yteach you about doing things without thinkng them through first? Not attempting to lecture, but i've heard of ppl doing dumb things like adjusting rails wildly then RMA'ing their blown PSU and MOBO etc.

[muzz]

Foxie

Those numbers fluctuate quite a bit, I think you said that you used a DMM and got the same readings.
If using a DMM gives ya the same fluctuation I think it's time for a new supply.

Edit: And I would get something with a much beefier 12v rail.

JMO