Instability with older machine

[wallie_x]

I have an older machine that I was thinking on giving away for a Christmas present to a kid down the block. However, in the not too recent past I have had big lock-up problems with this machine, especially when I had a MS DOS based OS in it. Usually when multi-tasking, playing music while surfing the web. I switched to Win XP, but that didn't solve my problems. What did was loading Win XP with the ACPI turned off in the BIOS. After all the H/A I was wondering if all along it was an inadequate power supply. I don't want this poor kid, who knows little about computers to get a H/A for X-mas.

Athlon T-Bird 850 w/ 200mhz FSB
Tyan Trinity w/ Via KT-133A chipset mobo (S2390B)
Apacer PC-133 384MB (1-256mb + 1-128mb stick)
FSB asynchronous 100/133mhz it runs slower than hell 100/100mhz so I haven't even tried.
Maxtor 20GB ATA 100 5600 RPM HD.
CD-ROM & CD-RW
Intel cheapo modem
250 watt 'Deer" PS

Also, when I was having big lockup problems, the case fan which ran off a power header on the mobo, would noticeably drop in RPM. After I turned off the ACPI it no longer does that, which made wonder about the power supply

[Bill in SD, CA]

You might want to run Memtest86 and make sure it's not a bad module.

250 is on the low side and you may be right about it's short comings.

Bill

[fourthbean]

You could also check and see if any of the capacitors on the motherboard are bulging and/or leaking.

[Siliconjunkie]

Also, when I was having big lockup problems, the case fan which ran off a power header on the mobo, would noticeably drop in RPM. After I turned off the ACPI it no longer does that, which made wonder about the power supply

I agree with you here. The older T-birds were power hogs. Do you have another PS to try?

[thronka]

You need AT LEAST 300 watts for those older t-bird machines.

[Bovon]

I concur with all of the suggestions. A bad transistor in one memory chip will cause a failure...depending of what data is being passed at the time, will determine if Windows allows it or not. Run memtest fully..and if ANY errors are noted, get some ram.

The power supply is high on the list as well..and it is not necessary for a PSU to be low on the output. Defective filtering can cause problems as well..trouble is, you cannot tell if the voltage output contains noise from weak or bad capacitors allowing a small AC component to show up in the output. Try another PSU if possible.

Look closely at the caps near the CPU socket. Most (or all) motherboard manufacturers were sucked into that trap with the manufacturer of capacitors from a stolen formula..they are still failing. I have repaired two boards so far that had them. Sometimes, (not always) you can detect a slight bulge at the top of the capacitor..the aluminum top should be very flat. Usually, when these capacitors fail..the machine will not boot..or takes several tries to get it to boot. These capacitors are in the Vcore circuits and phase network.

[wallie_x]

Thanks to all who replied!!
It was late after work (0030 hrs) when I wrote this so I forgot to mention: The noticeable drop in RPM with the case fan happened when I clicked and opened a new window, especially when web browsing.
Question: do the older T-Birds run on the +3.3v rail?
Looking at the PS the 3v rail has 16Amps the +5v has 25A, but the +12v has only 9A??? and I have a CD burner and CD-ROM. But it didn't lockup when using those.

Also, this is the second Tyan mobo. I RMA'd the first (rev. # 00) because I tried everything I could think of and the instability persisted. However, I never tried a higher watt PS. I could temporarily take the 300watt out of my daughters beast and run it on the one in question, but the Tyan system after disabling the ACPI only had problems running her kiddie programs which were not designed to run on Win XP.

Thanks again to all who replied!

[Bovon]

250 watts is not enough for any system which is running a CD burner. The laser in a burner requires much more power than a reader laser.

This may not have been the cause of the lockups since the burner was not running or burning when the system failed..but will probably create other problems while burning later on.