Low 3.3V Rail [Resolved]

[TheRagnarok]

My pc starting giving me random hard shutdowns.
I poked around and found that my 3.3 was around the 3.240 range.
Found that wiggling the 24 pin atx connector on mobo would bring it up to 3.296-3.312.
This keeps coming back, and as I'm typing this it is at 3.232 and if I hold moderate pressure on the 24 pin ATX it stays at 3.312 stable.
Remove pressure and it drops.
I've tried cleaning contacts with 99.9% isopropyl alcohol and the issue persists.

 

[sneekypeet]

Voltages are used with a + or - 10% (so 0.33V fluctuation either side of 3.3V) and they are still within specification. Although, on the flip side, having fluctuation in the connection cannot be a good thing.

 

[FR@NK]

It's actually +/- 5% for the 3.3v rail.

When you say "hold pressure" are you pressing down on the connector or are you bending the wires down? You should be able to get a replacement atx cable to see if solves the problem as its very unlikely that the motherboard receptacle would be faulty. Its possible to repin the cable but it isnt easy to get the old pins out even with the right tools.

 

[TheRagnarok]

Just pushing the connector into the motherboard like you were inserting it without too much force corrects the voltage drop.
Its a modular PSU so a replacement 24 pin ATX cable may be best.
Going to look for some now , thanks for the advice.

 

[Frick]

Still within spec tho, and why would it wiggle when being stationary? if it dies when you kick it I might agree that something is loose.

What are you measuring with?

 

[basco]

thats why most losts are between the connectors
and are we really talking bout a 0,016millivolt difference?
and if you say you measure with software then we should not be talking bout this.
even with a multimeter this is not a prob

how do you get to thats its the powersupply making faults and not other hardware?

 

[TheRagnarok]

Well guys I resolved the issue, it was the contacts on the ATX 24 Pin cable.
The prongs just needed to be bent back into shape.

I removed all cables from PSU and tested with a multi-meter after jumping the PSU-On to ground:
12.13
5.05
3.34
Looking good.

Powers supply is working as it should but the problem was with the contacts in the cabling.
It was fluctuating wildly on the 3.3v and 12v and actually hard restarted on me last night.
Plastic plugs were brittle and broke easily when I tried bending the prongs.
The pieces that broke off could be crumbled like cookie crumbs between your fingers.
And this gave me easier access to push the little prongs inward to make better contact.
I only did this on the 3.3v pins and the 12v pins.
To measure voltage I was using HWMonitor while in windows and the included Monitor in BIOS.

Everything is running smooth now at:
3.328v
5.040v
12.192v

This thing has about a year left on the warranty and I'm going to see if they will just send me replacement cables.
Its working great now and I may just make a new cable if it comes to it.
Will post pics if requested.

 

[FR@NK]

Glad its working, hopefully they send you a replacement.