my dual p3 pc is dying

[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.

[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?

[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.

[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

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

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

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".

[PCBONEZ]

Re: my dual p3 pc is dying

Your P-III motherboard needs -5v.
.

[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

Have an ISA slot?
Have any 16-bit IC chips on an ISA BUS?

Either of those requires -5v.

[Th3_uN1Qu3]

Re: my dual p3 pc is dying

Yes at both questions. I have an ISA soundcard. Well, at least, used to... My latest dual-PIII board does not have an ISA slot anymore.

[everell]

Re: my dual p3 pc is dying

What is the model number of that 250 watt LiteOn power supply?

Also, how many volts did you measure on +5 and +12 rails? On each of the two power supplies?

[PCBONEZ]

Re: my dual p3 pc is dying

Even if a P-III boad doesn't have an ISA slot it may have the ISA BUS to support 16-bit based Chips.
That situation was common for sound, LAN, PS/2, Floppy, and even some IDE controllers.
MSI actually continued using 16-bit chips w/ISA BUS [no slot, just the BUS] right into their early socket 478 boards. [Some.]
That was kind'a sleazy. Was basically an easy way get away with using cheaper IC chips.
Not sure if anyone else did it into 478.

The -5v isn't used for power as such, it's a biasing voltage. [-12v is too.]
That's why there isn't squat for amps on that rail.

Not all 16-bit chips need -5v but if some chip does and the chip isn't doing anything the board may work fine right up until that chip is called upon to do something.
Then it will likely throw errors, BSOD, reboot, lock-up or just shut off.

.

[shovenose]

Re: my dual p3 pc is dying

so what do i do?
the liteon model is: ps-5251-08

ok so: even if the 3.3 and 5v rails are being overloaded, it still has more amperage than the fsp 200w. im sorry i just dont get it. would a different psu:
enermax eg301p-v(e) its a 300w:
+3.3v: 28a
+5v: 30a
+12v: 15a
-5v: 1a
-12v: 1a
+5vsb: 2.2a
ill try this and let you know how it goes.
but t\what i think is wierd is that the pc worked just fine yesyetrday running prime95 for several hours...

[PCBONEZ]

Re: my dual p3 pc is dying

Does this board have OST or KZG caps?
Sudden death with no bloaters kind'a sounds like them.

[PCBONEZ]

Re: my dual p3 pc is dying

so what do i do?
the liteon model is: ps-5251-08

ok so: even if the 3.3 and 5v rails are being overloaded, it still has more amperage than the fsp 200w. im sorry i just dont get it. would a different psu:
enermax eg301p-v(e) its a 300w:
+3.3v: 28a
+5v: 30a
+12v: 15a
-5v: 1a
-12v: 1a
+5vsb: 2.2a
ill try this and let you know how it goes.
but t\what i think is wierd is that the pc worked just fine yesyetrday running prime95 for several hours...

Some newer spec PSUs need a minimum load on +12v and that P-III may not have enough, so yes, try a different one.

You can fake the extra load by adding 2 or 3 hard drives [don't need to connect data, just need them to spin up] to see if the PSU will kick-on that way.

Also if an existing drive ate it that can keep the whole system down.

.

[kc8adu]

Re: my dual p3 pc is dying

so put back the fsp already.the clue here is that it ran fine till you messed with it.

[Toasty]

Re: my dual p3 pc is dying


.

[PCBONEZ]

Re: my dual p3 pc is dying

The 1U FSP probably doesn't fit the ATX case real well.
.

[everell]

Re: my dual p3 pc is dying

1. Different case means different cooling ability. New case may be building up heat pockets which cause computer/power supply failure after a certain time period. Running dual cores, you might want to unsolder the power supply fan from its temperture controller, and solder the leads.....red to 12 volt rail and black to ground. Fan would stay on full blast all the time and make more noise, but you would have better cooling. Likewise, you may want to connect case fan directly to +12 and ground rather than plugging it into the mother board which has temperature controller and reduces fan speed.

2. LiteOn power supplies from that era use Chinese crap glue. Should look white, but after a few years turns yellow, then brown, then black. Also turns from gummy to brittle. Dark brown and black is resistive or conductive. Brittle sometimes has black holes inside the glue (you can see it if you poke at it with a small screwdriver and it crumbles). This indicates arcing. Glue which is shorting/resistive/arcing is stealing power from the power supply.

3. Bad caps which don't look bad - not failing totally but stealing power from your power supply. That power supply is old enough that a total recap with GOOD capacitors will improve performance.

4. Small pc board soldered to main pc board with supervisor chip. The small pc board has two potentiometers on it. The one on the left adjusts the voltage level for the +5 and +12 rails. The one on the right adjusts the +12 volt rail max current amount. Some of these older power supplies are running a little low on voltage, so they can be adjusted upward. Adjusting the one on the left, I try to set the +5 rail for 5.1 volts under a small load (one hard drive and one cd rom)