5v Drop....OC Problem

[Lonely Raven]

Howdy all. I have something I want to run past you and see
what you think.

I've got an ABIT KR7A-R with an Enermax Whisper 350Watt
PS, GeForce 3, 2 40GB IBM, 1 18.2g 10,000 RPM UW2 SCSI,
SB Live, 3Com NIC, and 120mm fan on a watercooled rig.
Oh, forgot to mention, I have Corsair 2400DDR and/or
OCZ PC3000DRR.

I'm having major problems overclocking a 1700+ past 145Mhz
FSB. I haven't gotten a chance to unlock it yet, I tried to do
it quickly with some superglue, tape, and silver pen, but I
guess it didn't unlock. I was kinda rushed that day.

I was looking over the system, and went as far as to remove
everything but video card, and SCSI drive (boot drive), and
it still wont OC past 145FSB.

So I'm looking at my MBM5 and see my 5v dropping to 4.84!!
WTF!

I read somewhere (here I think) about Enermax PSs dropping
the 5v and there being a mod for it. But I don't want to do it
unless I'm sure that's what my problem is.

And I've also had bad luck with my system boards having bad
caps and just running the voltages all over the place.

Oddly, this very same PS runs the 12v at a little over 12! Too bad
I can't do that to the 5v!

I'm really tapped for cash, so running out and buying another PS
is not an option, and I just found out that my damn Digital
Volt Meter is toast. The damn cheap assed Radio Shack
batteries corroded inside and the thing won't power on again
even after I've cleaned all the contacts and replaced all the
fuses...grrrr

Any suggestions? Any Help?

[Brad]

4.84v isn't an issue, the spec is between 4.75 and 5.25v, so that won't be an urgent thing, it's most likely your cpu needs more cooling or voltage to hit a higher speed

[Lonely Raven]

Ouch, I must be spoiled then...

I had one of those "Blue Meanies" that was a 750 that went
up to 1200Mhz, and I've also got a 1.333 Tbird that does
1660. Possibly more if I bother to water cool it.

Maybe I got a bum chip (hehe, or average if you want to
look at it that way).

But Hey, there is a computer show tomorrow...maybe I can
afford another one.

[Brad]

most xp's seem to overclock fairly poorly, but put some more voltage through it, you'll get a lot better result. Try 2v or more

[decodeddiesel]

Ugh, enermax stinks thats why your 5V is dropping a bit. The KR7A is much more forgiving on the Enermax than others like the 8KHA+. You are ok with those reading for now, but a Vmod will probably put you below 4.8 which I find is when stability is affected. If I were you I would purchase a new Antec 400watt or Sparkle 400watt, this would at least eliminate the PSU as being the limiting factor in your overclock.

[TigerOats]

This problem is normally associated with the 5V female connectors on the ATX not making good contact with the male on the mobo. The output of the PSU will probably be fine. To check whether this is the cause; with the system running feel the side of the ATX connector at the top and see if its warm. If it is then thats the cause. Using a multimeter measure the output of the 5V (red) on one of the spare molex connectors. If you want to go even further then look for the MOSFETS around the CPU. They are square and have 3 legs. They should be in pairs and you will probably have 6 of them. Again using the multimeter with the system running under load and taking the negative off the case put the positive lead on the center pin and get a reading off each of them. Make sure you only touch the center pin! half will read +-2V and the other half will read the same as your 5V line on the monitor. If you want to boost the 5V find a female molex connector and then solder the 5V line to one of the center pins of one of the MOSFETS. Must be a 5V MOSFET that you have measured. If you get the wrong one you can look for a new mobo. If this improves it but the reading is still too low you can make another connection to another 5V MOSFET.
If you want more info on this; http://forums.overclockers.ws/vb/sho...threadid=58333

[Brad]

measure the voltage on your molex connector, lets say it's 4.9v, then mbm says 4.84v, this means your psu is dropping .1v, while your mobo is dropping .06v. So your psu sucks more than your mobo (highly likely bearing in mind you have an enermax) In otherwords, a 5v rail mod won't change much.

If your psu is giving out 5.16v, and your mobo is giving you 4.84v, then your mobo is a piece of shit

[TigerOats]

Originally posted by Brad

If your psu is giving out 5.16v, and your mobo is giving you 4.84v, then your mobo is a piece of shit

Sorry Brad I don't agree. One of the factors with oc'ers is the fact that we are always fiddling which means the ATX plug is always being plugged and unplugged which leads to the female connectors becoming loose fitting. Has nothing really to do with the mobo or the PSU its about poor design. Need to find a better way of making ATX plugs particularly with the high demands now being made of the PSU

[Brad]

I know that, but I'm referring to when you first take it out of the box. The epox 8k7a series for example has huge 5v line issues

[EMC2]

Raven - This link may help you out

[TigerOats]

Originally posted by Brad
I know that, but I'm referring to when you first take it out of the box. The epox 8k7a series for example has huge 5v line issues

I would agree 100% with you on this and perhaps taking a 5V line directly to the MOSFETS would cure this. Anyone tried it?