I have just built a new system - MSI KT6 Delta - XP2500+ Barton running @ 42C - 512k Crucial PC2700.
This is not overclocked, running @ 166 x 11, Vcore 1.65v. I keep getting problems on boot up, as windows loads the power unit whines and the system reboots.
Yes I know the next answer - and on checking the +12v supply I found it dipped badly. Just brought a Jou Jye 550w (AMD approved) unit and guess what ? Yep still having the same problem.
Monitoring with a dvm shows the +5 and +3.3 rails rock solid, but the +12v still constantly wobbles around from 11.940 down to 11.888 at times. The +12 is rated at 32A max. If I plug a fan into the Mobo header it drops the +12v by a further .015v. This is driving me nuts as the problem is intermittant, so I wonder if anyone can shed light on this.

Thanks

John

Power rails shouldn't exceed +/- 5% of spec. You don't have a problem with that.

What does this whinning sound like from the Power Supply?? The fans maybe? Does the new powersupply have this same problem?

I'm thinking it's a problem with your motherboard.

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DFI nFII Ultra Infinity
Barton 2800+ [ 250 x 10 , 2.0V ] , SP-97
Mushkin Black Level II PC3500 [ 3.2V , 11-2-2-2.0 ]
Radeon 9700 Pro , WD360 Raptors [Raid 0]
Antec TC 550 , Klispch ProMedia 4.1

DLT3C 1800+ , 8rda+ , HyperX PC3000 BH-5

The whine occurs when it is about to reboot, it is happening on the new power supply. I believe it is the SMPS being dragged down by a momentary short circuit, the whine being the SM frequency changing. Problem being is it the M/B or the processor - both brought from different suppliers - and as it is intermittant they may check and find no fault. Catch 22 here I feel. No apparent voltage change at the time it happens, but I cannot see any other reason for the whine - havind said that the new PSU has overload protection so that may wash that theory out. The whine is definately coming from the power unit as I have the system "breadboarded" on my bench.

John

I concur with Drisler. Your 12v rails are not the problem especially if they do NOT exceed +/- 5% out of spec.

The mainboard is the intermediary between the processor and the CPU and thus could be the source of the problems.

Do you have another mainboard to test your new power supply on?

cheers,

dave

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I would run the motherboard outside of the case, or if you can't do that, put a sheet of that non-conductive foam underneath the motherboard, between it and the case. Pull all non-essential devices off - CD-ROMS, floppy drive, etc. See if reducing the loading or removing devices gives you back the stability you crave. If these don't work, look into driver updates; are you sure you loaded all the motherboard (chipset) drivers?

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I only build AMD machines. It's better that way....