Overtaxing PSU?

[Matt_H]

Hello all,

Having some trouble with my 4000T and I'm beginning to suspect it's the power supply. The PSU is fairly new and hasn't been used much, so it shouldn't be worn out at this point, but I'm wondering if it's just not powerful enough. My previous supply was 300W, which I thought was overkill, so when I found a replacement that was 230W I figured it would be okay. Perhaps not.

In short, do you think 230W is enough to power...?
4000T motherboard
CSPPC + replacement fan
5 Zorro cards
2 CD drives
1 (10,000 RPM SCSI) hard drive
1 floppy drive
1 case fan with LEDs

Symptoms are some slight instability, hard drive sometimes seems to stop and start spinning, trouble reading CDs. These seem to clear up if I disconnect a few things. Basically just looking to get some confirmation from the experts here before I plunk down $30 on a more powerful PSU

Thanks!

[Matt_H]

Even the new AT PSU's can fail.  While a more robust 300 or 400W AT PSU can be found on the web, you may want to check out your 230W  supply (which should be adequate for your hardware)  to make sure the voltage is constant under load without ripples and drop outs.  This problems will cause odd failures that are unpredictable.  Except for the mostly unused -12V line, an ATX PSU can be modified to supply the power and the mATX ones can fit into an AT style PSU box so the hardware lines up with the mountings.

Hmm, either way I'd be looking at a new PSU... may as well go for the drop-in AT replacement...

[Matt_H]

350W AT supplies seem to be a bit hard to find, unfortunately, but 300W ones are readily available.

Dan, it doesn't surprise me that your original PSU is still working. I think Chris is spot on that they don't make 'em like they used to. There isn't exactly much of a competitive market incentive for high build quality in AT PSUs these days . My 4000T's original PSU lasted from manufacture in 1996 until 2007 under a slightly lighter load, and I think it was 200W. The 300W replacement lasted 2007 until 2012 or 2013, and now it looks like the current 230W may be scrap-ready after only a few weeks of active use (though it's been physically installed longer).

I wonder if I should get 2 new ones so I have a spare...

[Matt_H]

Circling back to this, I was all ready to install a new 300W PSU until I discovered that it did not include a grounding screw. Probably not a huge deal, but there seemed to be some build quality issues with the unit to begin with, so I didn't want to take any chances. Did some more testing with the existing 230W unit, rebalanced the power load across the leads, and things seem to be ok for now. Hopefully I can return the new PSU to the store...

As to the trouble reading CDs that I mentioned in my first post, it looks like that was a problem with a particular CD. Silly me thinking a recent, commercially-masted CD would behave properly. Now the even more ironic part: it was OS4.1 Classic. Anyway, made a copy of the disc on another machine and the copy behaved correctly in the 4000T.

Now to start a new thread for the OS4 problems I'm having...