power cycles before booting like normal

[kwbbpc]

A new build I recently completed works just fine after it gets started up, but for some reason, when first turned on, the fans and lights turn on, then off about 2 or 3 times before any posting, and on about the 4th power cycle, the computer posts and loads windows without any problems or instabilities. This only happens when the CPU (Pentium D 805) is overclocked past a certain limit (somewhere around 140MHz). When the CPU is on stock speed, everything is normal.
Specs-
CPU - Pentium D 805 - overclocked to 165MHz (stock 133) multiplier x20 - CPU multiplier is grayed out in the bios (v 1102).
Mobo - Asus P5B (plain)
RAM - G.Skill DDR2 800 (2 X 1GB)
Vid - Evga Geforce 7600 GS

Any ideas/suggestions as to what could be wrong would be greatly appreciated. Thanks.

[minsonngo]

Brand and model of PSU?

[kwbbpc]

Tried 2 different PSUs:
Thermaltake W0070RUC 430W PSU - works fine in another computer.

I upgraded the PSU to a 500W Xion XON-500F8X2-201 thinking I may have inadequate power. Same exact problem with both PSUs.

[Alaron]

That Thermaltake unit is not ATX 2.0, required for any new build using PCI-E.

Xion PSUs are piles of junk.

Check out our inhouse list for a solid unit to get: http://forum.pcmech.com/showthread.php?t=131195 This would be a great choice: http://www.newegg.com/Product/Produc...82E16817104954

[kwbbpc]

Well, other than the stated problem, I haven't had any other issues yet with the Xion. Newegg reviews were decent enough for me to warrant a purchase. Considering that two different power supplies have been in this system, and the exact same problem occurs, I was thinking that the chances of it being a bad PSU were slimmer. I believe the Xion is version 2.2, so that should have eliminated the power cycling if that was the problem, correct?

[minsonngo]

Well that does not mean a PSU issue is out of the question. The first PSU you had was not ATX 2.x and the second one you have is a off brand one.

You need to get a hold of a QUALITY ATX 2.x PSU and see if your issue is resolved.


And... if the problem is only occuring when you have it overclocked... then you may want to consider lowering the settings or not overclocking at all. I have worked on computers all my life and I still do not understand people's fascination with overclocking.

[kwbbpc]

Overclocking...all about the numbers. Anyways, I'm gonna give a FSP Group (Fortron Source) AX450-PN and see if that fixes this problem. I'll update once it arrives.

[minsonngo]

Alright... let us know how it goes.

FSP is a good choice by the way.

[kwbbpc]

Upgraded to a FSP AX 450 PSU last night, and still having the same problem. When Overclocked above 140MHz it cycles once upon boot, and then past ~156MHz, it cycles 2-3 times before booting.