Unstable system!! POWER SUPPLY DEAD??? NEED HELP!

[metroplex]

I need help with this!!!!!!

My +5V dips down to 4.52V and XP Pro SP-1 just starts to act really unstable and crashes.

I checked EVERYTHING and I can't figure out why!

The system:
Enermax 650W ATX power supply (out of warranty)

Abit KX7-333
AMD Athlon XP 2100+, running 13 x 133 right now (it can run ta 138 - 142 so long as the +5V stays above 4.5V)
two sticks of Crucial PC2100 DDR, 256 x 2

Creative Labs SB Live 5.1 X-gamer
Linksys NIC
ATI TV Wonder PCI
Leadtek Winfast GeForce 3 TDH
Toshiba 16x DVD/48x DVD-ROM
Sony 40/12/48 CD-RW
Maxtor D740X 40GB
IBM 75GXP 75GB
1.44 floppy

Thermalright AX-7 heatsink
Thermaltake Smart Fan
Slot cooler
80mm intake fan
60mm Delta exhaust fan (19cfm)


The +12V and other voltages look nominal
IO is at 3.5V-3.65V
DDR is at 2.6-2.7V

VCore is at default 1.75V

its only running stable at 13 x 133 becuase the 5V is at 4.62V

I used to be able to run it at 13 x 142, then slowly had to drop to 138 - and today it crashed a number of times at 138 - and every time the +5V was 4.5x V

I prime 95'd this thing for 24 hours using 13 x 138 w/o any problems.

Any ideas on why the +5V would intermittently drop?
Bad power supply?

Should I get another power supply and run the +5V in parallel to one of the leads on the Enermax 650 and see if the Enermax can draw some current from the add'l power supply? This is a band-aid fix - I know.

But what part(s) could be sucking that much +5V where it'd drop to 4.5V???

My +12V is around 12.1-12.22V

I used this same power supply on an Abit KG7-RAID and got about 11.84V for +12 and 4.6V for +5

Please help!!!

Thanks in advance!

 

[mechBgon]

Sounds like time for a new PSU.

 

[metroplex]

Any recommendations?

AMD XP 2100+ CPU, two fast HDs, two optical drives (CD-RW, DVD-ROM), GeForce 3, quite a few fans
need some room to overclock also

 

[mechBgon]

Antec TruePower 430, Enermax 465-series, Sparkle Power 400W come to mind. The companies have good reputations.

 

[metroplex]

My Enermax 650W is what's apparently DOA.

 

[mechBgon]

I understand, but those are still the first three companies I think of as having a well-made power supply. I've had a couple of Enermaxes and they've done well for me, but nobody has a failure rate of zero.

 

[metroplex]

so you're positive that the low +5V is the result of a faulty PSU?

I lowered the FSB to 133, raised the IO to 3.65V and my +5V is now at 4.68V
and 12 is at 12.11V

Sometimes it'll drop to 4.52V for no reason (like when it was crashing like crazy).

What +5V and +12V voltages should I be seeing with an AMD XP2100+ and a similar motherboard/system setup?
5V and 12V?

 

[metroplex]

ok call me crazy... but:
I slapped on an old ATX 250W power supply JUST for the mobo and used my Enermax 650W for the rest of the system (HDs, fans, etc)

According to my BIOS I'm consistently getting 4.83V for +5V and 11.98V for +12V
That's a tad better than 4.52-4.6V but its still below +5V - now I realize this is a 250W supply probably rated much less in real life - but does this seem like its the 650W PSU that's malfunctioning?

I just wanted a 2nd or 3rd opinion before I go and buy a new PSU and try to fix the 650.

Thanks!

 

[DhootiMaDhamal]

Antec 430 truepower, stinks ... all my motherboard parts work, but won't power up mobo... bought a compusa 600watt for 80 bux. System works great... sometims cheap is better.

Dhooti

 

[metroplex]

Well I went to CompUSA and bought their 500W ATX supply for $80. The 600W was $100, and i didn't think I needed that extra 100W capacity anyhow.

I spent about $160 on the Enermax 650W supply last year, and figured I was buying a name brand supply that would give me years of trouble free service.

Apparently the cheaper PSUs work much better than the "name brands" that have "gold plated" connectors and "gold plated" fan guards. All of these PSUs seem to be made in China - I think the Chinese simply sell crap at a higher price and some of their more decent supplies at low low prices.

My 250W ATX supply from circa 1997 allowed my XP2100+ system to POST. However when I connected all of my drives - it wouldn't even start up.

My only gripe is that the CompUSA PSUs didn't mount that 2nd fan properly - it should go above the PSU like AMD recommends so that it vents out the hot air from the CPU and case.

I'll see how hot everything gets, but my main problem re: instability appeared to stem from the low +5V and NOT heat (I had it peak at 54-55C on Prime95 in the summer w/o any issues - then sometimes it fails to POST in 40F ambient in a cold start).

Right now my +5V is 5.05V and +12 is about 12.09V

Sound good?

 

[N2Ohyeah]

I recently upgraded from an ugly old generic CODEGEN(?) 300W psu to an Atlas 470w. The main reason was that I needed more molex connecters (full tower case)... The 3 clear fans and gold grills had nothing to do with it. Honest
Untill now I had been running the 300w for my CPU \ Mobo \ 1hdd and an older 250w for the CD'roms etc...

This PSU is great... Thermo controlled fans and 11 molex connectors.
Weighs a bit too, compared to the El Crapola generic ones.

Voltages, as MBM5 states are:
+3.3 = 3.55v
+5.00 = 5.03v
+12.0 = 12.16v
Core is always 0.06v over selected. Eg: 1.80 = 1.87 (mobo, not PSU i think)

Seems fine to me... This is apparently the same PSU as Enermax and ToPower - just the OEM version. Voltages are definitely more stable than the 2 generics. I had stability problems with the 250. TBird1200 @ 1450. Core V would sag, windows would BSOD. Hurrah.

I paid $165AU for this supply, and i love it. Thats about $90US or something. Remember, 'pooter stuff over here is real expensive

 

[spacelord]

I don't trust MBM5. I'm not sure how it can work perfect with EVERY motherboard.

my Bios says I have around +12v. MBM says 11.35. My Volt Meter says 11.74.. but my voltmeter is around 0.2 volts low after verifying it against a calibrated labratory power supply...

also MBM5 says I have -1.3v for my -12v supply. Also checking with the voltmeter, it is the same as my +12 but negative.

 

[metroplex]

im using the hardware monitor that came with my Abit KX7-333

Winbond Hardware Doctor

It lists the +5 and +12, and other voltages - they're dead on with the BIOS readings

but they're NOT dead on with my multimeter readings.

I figure that its taking the readings in the mobo somewhere - which is more accurate considering your CPU is probably feeding off the mobo and not your molex connectors.

My molex connectors all read slightly more than +5 and +12 on the 650, but my BIOS tells me otherwise.

FWIW I think I'll stick with the cheap Power supplies from now on.

I noticed Antec has a little footnote that states the max current output for the +3.3 and +5v combined is XYZ - which means those current ratings they give are BS and over-rated.

I didn't see such a footnote on my 500W CompUSA supply, and the math indicates the total wattage is 491W vs the rated 500W (prolly nominal vs. max) - which is fine by me.