I have a reliable test PSU that I use with all my hardware.
I also use a 240V-220V step down converter to protect old hardware that require 220VAC instead of the 240VAC we have now.
After cleaning I test every PSU I get for stability in a test computer. I measure output voltages under load. Since I'm only interested in pre-socket 7 systems I almost exclusively use AT power supplies. If a PSU is working right I don't replace any parts. If it's noisy or has bulging capacitors I replace them. I'm not into gaming or software tinkering so once a PSU passes my tests I consider it OK and into the PC it goes.

derSammler wrote:

The lesson to learn: Never leave old hardware connected to mains when you are not using them.

First thing I thought!

Also there is no such thing as "period correct" ATX PSU. If your motherboard is ATX - use it with some new, decent PSU (it doesn't have to be modular or have piano black finish and RGB LEDs installed). Those PIII and later machines already are power hungry, and PSUs from this period in general were of low quality (even 2 of my 4 Enlight PSUs have failed and those were pretty much top of the line). Not to mention it was almost capacitor plague era...

Keep in mind that failing ATX PSU will likely kill motherboard too (I estimate motherboard kill to PSU death ratio at 50% - based on my observations) - it wasn't the case with earlier AT PSUs (I don't think I ever seen any motherboard killed by failed AT PSU). On the other hand failing motherboard components (like VRC) can kill PSU as well and Abit was generally known for not being the highest quality/reliability brand...

Unknown_K wrote:

Many of the early ATX supplies were cheap junk and then you have bad capacitors that came later. You should pop the cover of an old PS and look for bulging caps and then test the supply with a PS tester that has an LCD for voltages (under $10 shipped on ebay) before you use it with a vintage machine.

s-l1000.jpg

DO NOT TRUST these testers. They are pretty much worthless - in many cases they will show PSU is fine, while it's not, or the other way around.
Use some test machine or at least artificial load and a proper multimeter.

Even a multimeter isn't enough. PSU safety testing requires scope shots for ripple and power on transients. The Bestec 250W motherboard killer pumped over 12V onto the 5V SB rail before settling down. Depending on the condition of the filter caps, SB voltage could stabilize fast enough to not be easily noticeable with a DMM while still being plenty to nuke your hardware.

Using an analog multimeter would make it plenty noticeable, though. I've got a 10V range on mine and it will show every little spike in that range. If it pegs the scale on 5V when you turn it off, you know it has that problem.

Allied power supplys are trash. What does period correct have to do with using junk that is known to fail.

Good analogy would be, this cheap knock off made in china part is 25 years old so becasue its 25 years old it is "period correct" so don't use period correct parts because they are bad. Meanwhile this high quality PC power and cooling, emacs, seasonic, "insert good brand and quality part" is bad too because its old too... 😲

Even good brands have failures. There's a lot factors to consider as cause of failure. the enviroment the unit has been operating in for example.

data9791 wrote:

This sucks. BIG TIME. This is exactly why I've been considering installing a picoPSU into my childhood 27 y/o Compaq Prolinea 4/33. It's my first computer and would be heartbroken if it died because of something like this.

Not a cure-all. Those Pico PSUs are built to be compact and cheap. And that means compromises. Smaller filter caps and inductors (often NO filtering on the 12V rail if it's designed to pass-through from a 12V source), and minimal protection circuitry. I reversed the +5v and Gnd leads on a Compact Flash adapter once and it smoked a Pico PSU. No over-current protection, just heat, smell, smoke. This isn't indicative of ALL Pico supplies, just be aware that it's not a perfect solution.

The reality is, all parts die. Sometimes they take other parts with them. If you're serious about maintaining authentic retro hardware, you need to disciplined about it. Get some tools, learn how to use them, and perform preventative maintenance from time to time. It's not a guarantee, but it'll improve your chances quite a bit.

Thanks everyone for the advice. I didn't know that Allied was such a poor brand to use. Their stated specs always looked better than all of the other power supplies that I found.
Fortunately though, every other component in the computer (Including the Geforce FX 5900 Ultra) checked out OK after I tested them in a BCM QS440BX motherboard. Unfortunately, that computer also has an Allied power supply.
I guess tomorrow I'll be voiding my warranty on some 19 year old power supplies to check for bulging caps.

Warlord wrote:

Allied power supplys are trash. What does period correct have to do with using junk that is known to fail.

Good analogy would be, this cheap knock off made in china part is 25 years old so becasue its 25 years old it is "period correct" so don't use period correct parts because they are bad. Meanwhile this high quality PC power and cooling, emacs, seasonic, "insert good brand and quality part" is bad too because its old too... 😲

You seem really angry for some reason.

Caluser2000 wrote:

Even good brands have failures. There's a lot factors to consider as cause of failure. the enviroment the unit has been operating in for example.

I have a rusted out old 486 sitting in my store room. It sat on the top shelf of a junk store... Outside. For ~20 years. They couldn't make it work so they just stuck it where it fit and called it a day. They gave it to me for free when I asked about it.

The motherboard was long since dead... Battery exploded and it was far beyond any type of repair. I mean almost everything on the board was corroded and it had even climbed some of the expansion cards over time, there was nothing left to save. I got a nice ceramic chip out of it, at least.

But this mad creation of a case... The LED panel still works. It will still show turbo speeds. The front LEDs for power, turbo, and disk still work.
The power supply still works, too.

It's rusted to hell, it sat outside for the better part of two decades, everything else in the case is pretty much long gone... But the PSU works just fine. Rock solid on all rails.

Environment can be attributed to some failures - But damn, do some of these things withstand abuse. Good brands have failures, but the best ones will go through hell and come out the other side.



(I still wouldn't trust this thing to run any board I care about for any length of time, but it just goes to show they're not all bad eggs.)

^That computer has more rust on it than my 1989 Ford Ranger.

the sad part about this is that athlon xp era PSUs with high 5v amps are not produced anymore

but for older AT power supplys there are converter cables on ebay that make your ATX power supply into AT power connector
so you can just use a brand new one and don´t fear burning your old loved motherboard

I checked my other 2 Allied power supplies, and they both look exceptional. The thing that dumbfounds me, is that the Allied power supply that blew up was new and never used since 2004.

more like exceptionally suspicious given that build year 2003=peak badcaps era. wouldn't trust any PSU from that time that doesn't have good brand capacitors and motherboards are pretty much the same story.

bbkcs wrote:

Thanks everyone for the advice. I didn't know that Allied was such a poor brand to use. Their stated specs always looked better than all of the other power supplies that I found.

And the company stated specs on junk power supplies are ALWAYS way overstated.

Take a look at some of the old Hardocp or JohnnyGuru power supply tests.

The crappy supplies are always overstated by a huge amount and would generally have catastrophic failures when put on the load testing machines.

Odd how so many butthurt enermax lovers are giving me shit when I just said that two 18 year old power supplies look fantastic, and pose no immediate risk. I hope your newest power supplies blow up and take out your momma's vibrators with them. Also, fuck this forum, there's nothing but elitism going on here.

all i'll say is early 2000s when I worked for a pc shop, I replaced those kind of psus a few times, and we thought they were so bad that when we bought cheap computer cases they would come in them free basically and we would throw them away and put better power supplys in them before selling them to customers.

I really have no idea what you're going on about. Old PSUs have old caps. 2000s-era PSUs have 2000s era caps, which come with a likelihood of being faulty. Modern PSUs are cheaper than they have any right to be, and so probably have junk caps. In all cases, you need to be vigilant, inspect early and often, and replace if in any doubt. There are precious few exceptions, usually fairly recent stuff that most people can't justify buying because it was built well and therefore costs more than something equivalent that also appears to work just fine. Not sure how that's elitism, but OK.