**Calling all Enermax users!**

[BatmanNate]

Hi,

I have a question regarding PSU's effects on system stability. Just recently I've began experiencing occasional stability issues, and I'm eliminating possibly causes, and the only one that really is still the variable is the PSU. The 12v was well within spec, however the +5v was about 4.7v average and the -5v was roughly 2.7 average. This seemed a tad out of whack to me, and I'm curious if this could be affecting stability. It just locks and hangs, no reboot, and usually it only does it in windows when I'm browsing around or using the net, not when I'm playing games or creating DIVXes. It's not a tempurature issue most likely, since it does not lock up when doing the most CPU intensive activities. The PSU is an Enermax 431watt. Another thing I noticed about this particular PSU is that the rear fan is never on. I don't know if this is heat activated or what, but it's never been operable, and perhaps the unit is semi-defective. Any thoughts on the subject are welcome, my system configuration is in my profile. Thanks,

Nate

 

[BatmanNate]

Anybody at all?

 

[TheCorm]

Fan should always ben on with a PSU.

When it went on my work PC, I replaced the PSU quickly as it kept making a high pitched whining, got hot and crashed the system occasionally. With a 430w PSU you wanna sort that asap!

Since a new PSU of that Kaliber is quite expensive you may wanna see if you can get a replacement fan, PSU's are not that difficult to get into.

Corm

 

[BatmanNate]

Well, the deal with the Enermax is that it has 2 fans, one on the underside that draws air up through it, and one on the rear to push air out. Hence, there is still airflow, just not as much. I was curious to know if any Enermax users could help me out with this? I could easily replace the fan if that is what the problem is, but I do not know if it is the fan, the control circuit, or what. Like I said, it is possible that it is heat activated. Also, I was wondering if my 5v rail voltages were that far out of spec.

 

[Yossarian]

What are you using to measure the voltages? I use Motherboard Monitor, and by default it incorrectly ties its-5V channel to the VDIMM line, which is about 2.7V. This is with an Epox EP-8KHA+ and Antec 300W PS.

 

[Nack]

1. The fan should always be on, just at varying speeds depending on how hot your PS is. Possible causes are a loose connection within the power supply (where the fan connects to the connector on the PCB) or a dead fan.

2. The 4.7V +5V rail may be the cause of your instability issues. A low +5V rail is a known cause of instability problems on many motherboards. I had a problem with my Epox 8kha+ rebooting randomly that was fixed by raising the +5V rail on my PS.

3. The fix for both of these problems can be dangerous, and involves opening your power supply. If it is under warranty, I would advise you to send it back to Enermax, rather than open it. If it is not under warranty, or you are fearless (and careful), there may be a solution that you can do yourself.

FIRST: 1. Do not open your power supply - that is my adivce. DO NOT open it. 2. If you do, make sure the capacitors are FULLY discharged before doing so. There are various methods that people use to do this. One method that may work is to unplug the PS from the wall, while leaving it fully hooked up to the computer, and punch the computer's power switch. When you hit the switch, you should see the PS fan (the big one) spin for about 1/2 second. This is your PS at least partially discharging into your computer. It is wise to leave it sit fully disconnected from everything for at LEAST 6 hours (some say 3 days) to let the capacitors finish draining.

The reason for all of this, is that if you touch one of the capacitors while charged in your open power supply, you can die. IF you do this, therefore, ALWAYS work with a friend (who is NOT touching the PS) so that he/she can call the paramedics for you if you screw up.

All that said, IF you open the PS, the fix for the dead fan is to check the connection (will be obvious when it is open) and if that doesn't work, replace that fan. There are replacement fans that are temperature sensitive available to replace your enermax fan. If you are careful, you can probably even find the SAME fan - they are available.

The fix for the low +5V rail is to add a 1kohm potentiometer in series with R82 on the PS's PCB and adjust it to bring your +5V rail into spec. This requires being handy with a soldering iron.

The link for the Enermax +5V fix is here:

Enermax +5V PS Mod

After I did this fix on my Enermax power supply, my random rebooting problem was completely fixed.

Again, just to recap:

1. This is dangerous - don't do it.
2. If you do it, do it at your own risk, read that WHOLE thread carefully, and take all recommend precautions.
3. This will void your warranty so badly that it isn't even funny, so it is probably better to send your PS back to Enermax rather than attempt any of the above.

Nack

 

[BatmanNate]

Nack,

Thanks for all the info and the link, I'll give it a try when I get home and report back. (If I'm still alive and kicking)

 

[Nack]

Good luck, and don't forget to discharge those capacitors. We want you to keep posting.

Nack

 

[Nack]

By the way, how do you like the XP1500 SMP setup? I was going to build a dualie of my own, but then AMD gave me ONE XP2000+, and my nephew needed a computer, so I just gave my nephew the cheap Gigabyte board AMD gave me, and bought this Epox board for my free 2000+. It does everything I need it to do, and is blindingly fast, but I still wonder what could have been with my planned XP1600+ dualie that never happened... I'm still thinking of doing an SMP setup at some time in the future, but I'm definately going to wait for the .13 micron procs to get cheap first.

Nack

 

[Mem]

I`m using the Epox 8KHA+ with an Enermax 431w PSU but I don`t have a lot of hardware ,anyway I get 4.95-5.00v rail reading,I did have a look at your PC rig specs and you do have a lot of hardware which most is listed below,anyway if the mod does not work try the bigger 550W Enermax PSU.



<<
AMD Dual Athlon XP 1500's (1.33 GHz) 2666MHz @ 2666MHz
IBM Deskstar 75GXP 45.0 GB @ 7200 RPMS
Motherboard: Tyan Tiger MP
1024 MB of Crucial PC2100 DDR
4x60 GB RAID-0 array (240 GB)
(Media)
PNY Verto (GeForce3 Ti200 OC'd 250/550)
Maxtor 45 GB IDE 5400 RPM (SWAP)
DVD Manufacturer & Model: Pioneer 16x40 Slot
CDR/CDRW Manufacturer & Model: TDK VeloCD 24x10x40
SB Live! Value
PromiseUltra 100
Promise FastTrak Tx2
3com 10/100 NIC

Notes: I ditched the water cooling in favor of dual Athlons. The case is modded to include window, UV Lamps, blue LED's, 4 80mm Circulator fans (2 front, 2 back) Audio is connected to a 400 watt surround reciever and a pair of 220 watt 15's. Rigged for dual monitor operation. >>

 

[Nack]

The bigger PS probably won't do it for him. I've actually got the 550W version of the Enermax, and it puts out plenty of power, but I still had the instability/rebooting problem, and the only thing that fixed it finally was the +5V mod. The problem with SOME of the Enermax power supplies is that they used a cheap resistor with +/-10% variability in the circuit that monitors motherboard feedback to determine the +5V rail. Basically, the value of that resistor needs to be increased a little bit (at least within a higher range) for the Enermax to function properly with SOME motherboards that are picky about their +5V voltage. Word has it that in its latest releases, Enermax MAY have fixed this problem (by using a better and/or slightly higher valued resistor), but a lot of Enermax PSUs older than a few months do have this issue, even the great big 550W behemoth like mine.

Nack

 

[WarCon]

I think the next powersupply I go with will be a PC Power and Cooling. I like my Enermax, but I had to do the voltage mod to raise my 5volt rail too. I used a fixed resistor, instead of a pot. I don't trust pot's. If it fails for any reason and opens (infinite resistance), then the rail will max and probably kill you mobo (at least).

 

[BatmanNate]

Warcon,

What value fixed resistor did you use? Can you pick this stuff up from Ratshack easily? Also, anybody know where to get a nice FINE tipped soldering iron? Thanks,

Nate

 

[BatmanNate]

Nack,

For what I do, this duallie setup is heaven on PCB. Fast, stable, and relatively inexpensive. (I got 1GB Crucial ECC DDR 2100 back when it was $150 shipped for the whole thing) I hear that the TigerMP may even boast support for the .13u chips, that will certainly be my next choice in upgrading if this is true, once they are affordable at any rate.

 

[WarCon]

The value I started with was half of the pot size (470 ohm, I believe and yeah I got a resistor pack from them some time ago and still had a bunch) from the mod and it worked great for me. I was dipping down to 4.73 and now the lowest I have seen is 4.90 on my +5v rail.