my dual p3 pc is dying

[Th3_uN1Qu3]

Re: my dual p3 pc is dying

Your P-III motherboard needs -5v.
.

If it needed -5v it wouldn't have booted at all. My PIII mobos do NOT display video when the power supply feeding them doesn't have a -5v rail.

[PCBONEZ]

Re: my dual p3 pc is dying

Your P-III motherboard needs -5v.
.

[Th3_uN1Qu3]

Re: my dual p3 pc is dying

i dont have any other extra psu to use in this under 450w, which i dont want to "waste" with this... why wouldnt it work? this psu was runing an hp dualcore...

Different CPU, different voltage distribution. Thing is, the PIIIs use a whole load of 5v and 3.3v. And since 3.3v is derived via a magamp from the 5v rail, in effect, loading 3.3v is loading 5v. Also, they use next to nothing (practically, just what the hard disk, optical drive and video card use), of 12v, so the problem is worsened exponentially.

Basically, a computer power supply is intended to stay in spec while the same amount of power is being drawn from each rail, until maximum spec is reached. More or less, but anyway, they are designed for symmetrical loading, at least till 450W or so. Anyway, all but the latest power supply designs are group regulated. Meaning, if 3.3 or 5v go down, 12v must go up, and vice versa. To prevent the 12v rail from going high enough to burn stuff up, manufacturers allow the 5v rail to go quite (read: very) low. On my Xilence, with 12v at 12.7v, the 5v rail is allowed to go down to 4.48v, which is (besides WAY OUTSIDE OF ATX SPECS), low enough to not be able to run any kind of computer expecting +5v power.

On the other hand the P4s and later switched the CPU power to the 12v rail, which improved things somewhat. This is why that power supply of yours is able to run a "hp dualcore".

[shovenose]

Re: my dual p3 pc is dying

i dont have any other extra psu to use in this under 450w, which i dont want to "waste" with this... why wouldnt it work? this psu was runing an hp dualcore...

[Th3_uN1Qu3]

Re: my dual p3 pc is dying

Hmm, should be enough. However, do try with a beefier PSU. My Xilence has 27A on the 5v rail. It was enough when the CPUs were running at 1.05GHz/1.35v due to the old mobo's 100FSB limitation, however at their rated frequency and voltage, not mentioning overclocking, they need extra juice.

[shovenose]

Re: my dual p3 pc is dying

old fsp 200w:

+3.3v: 14a
+5vsb: 2a
+5v: 20a
-5v: 0.3a
+12: 6a
-12v: 0.8a

new liteon psu:
+5: 25a
+3.3: 18a
+12v: 18a
-12v: 0.8a
+5vsb: 2a

caps look ok

[Th3_uN1Qu3]

Re: my dual p3 pc is dying

The PIIIs eat GOBS of power on +5v and +3.3. That is probably your issue.

I got dual 1.4GHz overclocked to 1533 and my temporary set up needs TWO power supplies to run them. Check that the power supplies you got have at least 20A on the 5v rail, else it's time for something bigger.

[seanc]

Re: my dual p3 pc is dying

Put the 200w FSP PSU back in and test again - even if it's temporarily ugly.

Have you checked the caps in the 250w Liteon?

[shovenose]

specs:
dual cpu p3 1ghz
2gb ram ( i think its ecc)
36gb maxtor 10000rpm scsi
cdrw
liteon 250w psu
atx case.
so heres the story:
i took the cpu, mobo, ram, hdd out of an old 1u server case and stuck it in an atx case i had. it fits theres just no backplate around the ports. but that doesnt bother me...it was running on an fsp 200w psu originally. so u thought hey ill put in a liteon 250w. and this computer seemed to work great for the last two days. i had it running prime95 for like 4hrs yesterday...all was ok, so i shut it down...
this morning i do to turn it on. it starts up, and i open internet explorer and have 2tabs: tomshardwareforums and this site. and then about 10mins into use i get a bsod. so i hold down power, and then boot back up. within 2 mins it freezes (no bsod).
restart again. same thing 2 mins later it freezes (no bsod)...

other info:

BSOD MESSGAE; IRQL_NOT_LESS_OR_EQUAL iirc...
-hdd makes terrible noises at startup (always has since it was given to me) but a hdtune error scan claims its a-ok.