ATX power supply

[Christian McArdle]

I have a machine that has gradually been upgraded, one bit at a time. It
started off in 1989 as a 386DX20, and is now an Athlon XP 2600+, having
passed through many incarnations along the way.

Recently, it has started hanging dead upon disk access, but only during
heavy access. Can I assume it is because the old ATX power supply is
woefully inadequete?

I've already replaced the hard disk, as it was only on the 60Gb that caused
crashes. The old 20Gb was solid. However, the crashes still happen on the
new 120Gb SATA one.

I presume this is because the larger disks take more power? Given the
failure under heavy load, I suspected it as a possibility before even
replacing the disk, but needed more space anyway, so thought it worth a
punt.

Am I right in thinking that the old power supply is likely to be the cause?
It is a high quality one that came with a nice full tower case, but several
years ago and is only 235W, given that I think the motherboard was a 300MHz
K6 or something at the time.

Christian.

 

[Michael Hawes]

I have a machine that has gradually been upgraded, one bit at a time. It
started off in 1989 as a 386DX20, and is now an Athlon XP 2600+, having
passed through many incarnations along the way.

Recently, it has started hanging dead upon disk access, but only during
heavy access. Can I assume it is because the old ATX power supply is
woefully inadequete?

I've already replaced the hard disk, as it was only on the 60Gb that caused
crashes. The old 20Gb was solid. However, the crashes still happen on the
new 120Gb SATA one.

I presume this is because the larger disks take more power? Given the
failure under heavy load, I suspected it as a possibility before even
replacing the disk, but needed more space anyway, so thought it worth a
punt.

Am I right in thinking that the old power supply is likely to be the cause?
It is a high quality one that came with a nice full tower case, but several
years ago and is only 235W, given that I think the motherboard was a 300MHz
K6 or something at the time.

Christian.

Not only is that PSU a bit on the low side, but if it is years old or
more it will be performing worse than when new due to ageing components.
treat yourself to a 450W good quality replacement.
Mike.

 

[Mr. Slow]

I have a machine that has gradually been upgraded, one bit at a time. It
started off in 1989 as a 386DX20, and is now an Athlon XP 2600+, having
passed through many incarnations along the way.

Recently, it has started hanging dead upon disk access, but only during
heavy access. Can I assume it is because the old ATX power supply is
woefully inadequete?

I've already replaced the hard disk, as it was only on the 60Gb that caused
crashes. The old 20Gb was solid. However, the crashes still happen on the
new 120Gb SATA one.

I presume this is because the larger disks take more power? Given the
failure under heavy load, I suspected it as a possibility before even
replacing the disk, but needed more space anyway, so thought it worth a
punt.

Am I right in thinking that the old power supply is likely to be the cause?
It is a high quality one that came with a nice full tower case, but several
years ago and is only 235W, given that I think the motherboard was a 300MHz
K6 or something at the time.

Christian.


Your faithful 235w PSU is unlikely to be capable of providing sufficient

current to power a modern PC. Upgrade it to a quality unit of at least 400
watts.

Remove ".invalid" and replace with ".co.uk" to reply by e mail

 

[Bob Knowlden]

This site may oversimplify things quite a bit, but it may be suggestive:

http://www.jscustompcs.com/power_supply/

PC power supplies are not created equal: ones with the same power ratings
can vary quite a bit in terms of useful current. One of the critical
parameters seems to be the current rating on the +12V line. My Thermaltake
power supply is rated at 420W, but it claims to be able to deliver 18A on
+12.

235W sounds a bit low, even if the supply is a good one.

If your mainboard has monitoring hardware, you could try watching the
voltages. One freeware item that was good for this was Motherboard Monitor
(http://mbm.livewiredev.com/). It can be slightly painful to configure, and
its author has stopped further development of it, but it worked well. (I own
an Asus mainboard, so I use their utility.) If the voltages change out of
the ATX spec range (+/- 5%), that would be a sign of trouble.

HTH.

Bob Knowlden

Address may be scrambled. Replace nkbob with bobkn.

 

[Papa]

I assume you are still using the original AT (not ATX) case, but you said
you have an ATX power supply. If so, how did you get the ATX power supply to
work? The AT case on/off and reset switches are not compatible with an ATX
power supply.

Anyway, I think it is time for you to go to an ATX case and a 400 watt ATX
power supply.

 

[Matt]

I assume you are still using the original AT (not ATX) case, but you said
you have an ATX power supply. If so, how did you get the ATX power supply to
work? The AT case on/off and reset switches are not compatible with an ATX
power supply.

Suppose you have a knife. You replace the handle after four years.
After another five years you replace the blade. Is it still the same
knife?

 

[Papa]

Hmmnnn. I suppose it would be a restored knife. I've got several like that.

 

[David Maynard]

I assume you are still using the original AT (not ATX) case, but you said
you have an ATX power supply. If so, how did you get the ATX power supply to
work? The AT case on/off and reset switches are not compatible with an ATX
power supply.

It's not that hard. An ATX will mount in the AT hole, but it'll be 'upside
down'. Then you just replace the power switch with a momentary.

The rest switch doesn't need any change.

The bigger problem is the motherboard as the ATX extends further toward the
power supply than an AT so if it's a mini-tower, for example, it won't go
in, using the same mobo mounting holes, as it would intrude into the PSU. A
full tower usually has enough extra space to allow it though, if you use a
dremel to cut out the I/O plate area in the case rear.

That's what one of my home theater systems is in: a modified old AT full
tower that was originally a 486DX2/66.

 

[Zotin Khuma]

Suppose you have a knife. You replace the handle after four years.
After another five years you replace the blade. Is it still the same
knife?

My wife's office machine was originally a Pentium 166 Classic, 1GB
HDD, 4MB EDO, SiS 6215 display, Win95, 14" monitor. Her boss, a family
friend, asked me to upgrade it from time to time. It gradually evolved
through a Celeron 600, 810e mobo, etc. and now it's an Athlon XP 2400+
on an Asus A7N266-VM, 256MB, 40GB, CD-writer, TV tuner, WinXP, 17"
flat-screen.... !! Never was it replaced entirely at any one time.
Maybe it'll next become an AMD64

 

[Christian McArdle]

I assume you are still using the original AT (not ATX) case, but you said

you have an ATX power supply. If so, how did you get the ATX power supply
to work?

Nah. I got the ATX power supply with the case, at the same time as the
motherboard and processor. However, the hard disk, keyboard, mouse, monitor,
graphics card and memory (I think) didn't change at this time. Previous to
this particular upgrade, it was an AMD 486DX4/100. I think it went:

386DX/20
486SX/25
486DX4/100
K6/300
K6/500
Athlon/1200
Athlon XP/2600

Anyway, I think it is time for you to go to an ATX case and a 400 watt ATX
power supply.

Well, I got a new case, with a 350W AMD approved PSU and it now seems to
work, so power supply it was! It is hardly loaded with peripherals, so I
doubt the extra for a 400W PSU would have been worth it. The case I bought
was 40 quid (70 of your US dollars) and looks pretty, too!

Christian.

 

[Papa]

If you originally had an ATX case and an ATX power supply, then how did you
have a 386 or 486 CPU? They came later.

 

[Christian McArdle]

If you originally had an ATX case and an ATX power supply, then how did

you have a 386 or 486 CPU? They came later.

At that point, the case was AT. It is now on its fifth case...

Full size AT desktop
AT minitower
AT full tower
ATX full tower
ATX midi tower

Christian.