power problem in 3.3V supply, help needed

[janitha]

Asus Probe shows a warning in my computer that there is problem with the 3.3V supply. It shows the voltage as 2.75 only. Till yesterday it was around 3.25V. For the last 6 months since I assembled it, there had not been any problem and all the voltage were well within the 5% tolerance. What may be causing the problem? Which components use the 3.3V. And what is the remedy?

A64 3000, A8N-E, Transcend 512x2 -400, 80 GB Hitachi SATA, Sony DRU 810A, Priya 400W SMPS, 4 cabinet fans, Win XP SPII with all critical updates.
No FDD

Pl help.

[janitha]

once more I request somebody to clarify

[janitha]

Somebody pl help since the voltage is still going down.

[kalpik]

Dunno why its going down, but vcore (3.3) is used by the processor.
Read more here: http://www.pcmech.com/show/processors/189/

[ramprasad]

check with the speed of the fans... If it is intermitent or slow, then the fan is the culprit, it draws more current, hence the voltage shud be low......

Take the SMPS to any electronic shop and check it...
If fan is the problem, hope u will not mind tremoving it off, to make the voltage steady...


I faced the same problem and replaced the fan with a new one....

[gary4gar]

also use a ups to keep external voltage fultutions miles away

[janitha]

Thanks kalpik, ramprasad and gary4gar for the valuable suggestions. I will try them out and report back. But I was thinking that the fans or at least most of them use the 12V rail.

And I am using two separate 600VA UPSs, one for the Monitor and other for the system.

[janitha]

Originally Posted by ramprasad

check with the speed of the fans... If it is intermitent or slow, then the fan is the culprit, it draws more current, hence the voltage shud be low......

Take the SMPS to any electronic shop and check it...
If fan is the problem, hope u will not mind tremoving it off, to make the voltage steady...

I faced the same problem and replaced the fan with a new one....

Thanks a lot. Due to having been quite busy, I could try out your suggestion only today. As you said, one of the fans was the culprit. I disconnected the fans one at a time, each time restarting and checking the voltage until finally I could isolate it. Now the voltage is as fine as before.

And thanks again, because I could otherwise have gone for an Antec to solve the problem.

But still I cannot figure out why it should affect the 3.3V rail instead of the 12 V, which remained 11.9+V all the time.