Originally Posted by Starbomba
On my second job i tend to diagnose and revive very old computers based on PII, PIII, and old Athlons, like the K6's (they either need to run specialized software on older OSes, don't really need to be upgraded, or owners are cheap people).
Some of these PC's have gotten the PSU damaged, and i usually replace them with el cheapo ATX v1.3 PSUs since these are built towards +5w. Still, these are not even quality ATX v1.3 and i've never trusted them.
But if i were to use, say, a CX430v2, which is a ATX v2 PSU, based around the +12v rail, would they be able to feed an old pc like this? Some of these PCs have old SCSI cards, PCI video cards and other older toys, so it's not an "average" PC.
They would not, especially PSUs like the CX430v2, which have what's called a "group regulated" design. These PSUs require the amount of +12V and +5V current drawn to stay close to a certain ratio, or the voltages go wonky. So if you draw too much +5V and not enough +12V the voltage will go way out of spec.
For instance, running an old Athlon XP system off the similarly-designed Antec EA430 (from SeaSonic) the +12V ran at 12.64V (out of spec) and the +5V ran at 4.78V (almost out of spec) and the system was unstable.
For ATX units (as opposed to ATX12V/EPS12V) I recommend this unit: http://www.newegg.com/Product/Produc...0w%20atx%201.3
It's a decently built ATNG with adequate performance. It won't be winning any awards, but it's reliable enough.
Additionally, I have a Zippy AP2-5300F-R2 which is among the best ATX PSUs I've come across. I've dismantled the system so the PSU is available for sale if you want it. It's loud, but extremely reliable, so I recommend it for old enterprise systems. These are no longer sold (the last known source, Jameco.com, ran out last year), so me and Tator Tot are your best bet for getting them.