OC'ed PIII 700 will only POST when warm enough?!

[The Dup]

Looking for advice regarding my 1st OC experience resulting in the PC refusing to boot up completely until the 4th or 5th try, when the "PC is warm enough". What gives?

Configuration:
Generic ATX case with no active cooling
Generic 250W Power Supply
ASUS P2B Rev1.02 mobo with V.1012 BIOS
Pentium III 700 FC-PGA form sitting in an ASUS S370-133 slotket @ 1.8V
Stock Intel fan & HS on CPU
1 DIMM 128MB PC100 generic RAM
1 DIMM 128MB PC133 Crucial RAM
ASUS V700 GTS2 32MB video card 2XAGP
Quantum 7.6GB EIDE on primary master
Iomega Zip-CD 24X4X CD-RW on secondary master
Panasonic 40X CD-ROM on primary slave
Maxtor 13GB EIDE on secondary slave
3COM PCI56Kbps modem
D-Link 10/100 Ethernet NIC PCI

My first (and only!) OC step consisted in upping the FSB to 112Mhz using jumpers. The PC hums along at only 784Mhz, but at a cool 34 degrees C on a hot day with SiSoft Sandra running benchmarks continuously. After a couple of weeks with the system constantly up and running with no problems whatsoever, I thought I had a stable system and could safely switch it off at night. Well, what a surprise it was the next morning when I could not turn it on again!

It seems the PC refuses to power up again if it has been idle for a long time (i.e. overnight). When I manage to turn the power supply on, I hear all the fans speeding up, the HDDs spinning up, then the PC dies, goes off completely without a single beep. Flicking the power switch on and off does nothing; I have to unplug the power supply from the power cable, flip its power switch in the back on and off, plug the power supply cable back in, and can then push the main power switch on and hear the system go through its POST motions again, going a little further this time, even hearing the single beep signalling everything check out OK. And then, boom! It goes off again, even before the screen (which is always on) shows anything. I then go through the same motions with the power supply cable, and get a little further still, until after 4 or 5 tries it boots completely and remains stable.

The only solution right now is to to leave it on all night and all day, when I can only use it at night when I'm at home; what a waste!

What is the problem? Power supply not pumping out enough voltage? 1.8V not enough on the PIII? Should I go back to 100Mhz FSB? Or should I upgrade the mobo to a 133Mhz version and get a bigger power supply ($$$ not a problem)? If upgrading, what mobo should I get for S370?

Any help would be appreciated. Thanks in advance,

The Dup

[Pinky]

I think you're doing everything OK... try resetting the bios (the jumper near the battery probably), have it boot, go into the bios and make sure the default settings are all correct. Boot at defaults, into windows, then shutdown. Power her back on, if she boots into windows you know the overclocked cpu is the cause.

If it does boot the second time, then bump your voltage by .5 increments (no higher than 1.95 with the stock hsf). watch your temps never reach 50C (that's my magical number for too hot). Raise your fsb slowly... the first freeze will be the indication it won't go higher. Back it down one step (125 back to 112, etc). If your board is only a 100MHZ (like mine), you may need to cool the bus processor on the board or getting a mobo upgrade to make 133+.

Now, if it doesn't like the reboot and refuses to post/powerup, first try only the stick of 133 RAM, then the 100 -- see if that works. Running the 100 and 133 together may be causing some issues...

There could be other things to try, but that should keep you busy and eliminate some of the more common problems first.

[The Dup]

Pinky (Jun 20, 2001 01:28 p.m.):
I think you're doing everything OK... try resetting the bios (the jumper near the battery probably), have it boot, go into the bios and make sure the default settings are all correct.

>>> Do you mean reset FSB down from 112Mhz to 100Mhz? Or do you
>>> mean step down BIOS to pre-V.1012?

Boot at defaults, into windows, then shutdown. Power her back on, if she boots into windows you know the overclocked cpu is the cause.

If it does boot the second time, then bump your voltage by .5 increments (no higher than 1.95 with the stock hsf). watch your temps never reach 50C (that's my magical number for too hot). Raise your fsb slowly... the first freeze will be the indication it won't go higher. Back it down one step (125 back to 112, etc). If your board is only a 100MHZ (like mine), you may need to cool the bus processor on the board or getting a mobo upgrade to make 133+.

>>> Yup. The P2B Rev1.02 is a 100Mhz FSB board only, with jumper
>>> settings for 112 or 133 only.

Now, if it doesn't like the reboot and refuses to post/powerup, first try only the stick of 133 RAM, then the 100 -- see if that works. Running the 100 and 133 together may be causing some issues...

>>> I suspect that too, but it misbehaved so with only the PC100 no-name
>>> RAM installed. I should probably try just the PC133...

There could be other things to try, but that should keep you busy and eliminate some of the more common problems first.

>>> Thanks for the info. It will take me a while to try all of this as this is the
>>> main family-hold PC and my gamer-son will kill me if it is "off" too long.

The Dup

[outhouse]

Some NIC cards do not like there PCI bus speeds being raised at all also ive heard that if you use one stick of memory thats 100 and one thats 133 then they will both run at 100 so you will want to pull the generic stick out as that may be your problem. generic ram sometimes also does not like to run on out of spec speeds, unless you get better cooling like a new heatsinkfan do not raise your CV your temps are fine where there at now but i would not let them get any hotter, when you overclock a CPU they can get tempermental about temps one goal of mine is to keep my temps the same no matter how high i overclock i would not let my CPU get into the 40's at all, [it may not hurt it but it can bring on some instability] if you raise your CV then get some good thermal compound on your CPU as well as a couple of fans for your case.

OH as long as your temps are in the 30C range then raising CV will not hurt anything as long as you dont go too high.