Replacing power supply of PIII system with one from dell?

[Jef Driesen]

One of my old PIII system (500 MHz if I remember correctly) suddenly
won't boot anymore. Sometimes I can get as far as the boot screen and
than stops abrupt (e.g. like when unplugging the power cable). But most
of the time it doesn't boot at all, and it remains completely dead.

I tested with the power supply unit (psu) from a similar system and
everything goes well again. So I tried to get my hands on a new psu. I
could recuperate one from a dell optiplex GX1 (also a PIII system).

But when I replace the bad psu unit with the one from the dell, remains
dead. The dell psu is certainly good, because the dell pc is working.
There is a difference in the power of the units. The bad unit is 300W
and the dell is only 200W. But with the unit from my test system (230W),
it works perfectly, so I don't think this is the problem. I always
tested with only the mainboard connected (no optical or hard drives), so
power consumption was always minimal.

Is this dell power supply not compatible with a standard ATX unit? And
is there anything I can do about it?

Bad system:

* Mainboard: ASUS P2-99
* Processor: PIII (slot 1)
* PSU: 300W ATX

Dell Optiplex GX1

* Processor: PIII (slot 1)
* PSU: Dell PS-5201-7D

 

[Noozer]

One of my old PIII system (500 MHz if I remember correctly) suddenly won't
boot anymore. Sometimes I can get as far as the boot screen and than stops
abrupt (e.g. like when unplugging the power cable). But most of the time
it doesn't boot at all, and it remains completely dead.

I tested with the power supply unit (psu) from a similar system and
everything goes well again. So I tried to get my hands on a new psu. I
could recuperate one from a dell optiplex GX1 (also a PIII system).

But when I replace the bad psu unit with the one from the dell, remains
dead.

And most likely is damaged at this point.

Many Dell PSU's do NOT follow the ATX wiring standard. Check the wires on
the old PSU against the ones on the DELL PSU. They don't have to be the same
colour wires, but the number of each colour wire and their positioning must
match.

 

[Jef Driesen]

And most likely is damaged at this point.

Is it the motherboard that will be damaged or the dell psu? The
motherboard would be bad news. But I'm not worried about the dell psu,
because I have more than one.

I didn't see any smoke (or anything like that) coming from the
motherboard, so there is some hope left...

Many Dell PSU's do NOT follow the ATX wiring standard. Check the wires on
the old PSU against the ones on the DELL PSU. They don't have to be the same
colour wires, but the number of each colour wire and their positioning must
match.

I found an article about the issue [1]. And it seems possible to change
the wires to obtain a true ATX connector.

[1] http://www.quepublishing.com/articles/article.asp?p=339053&rl=1

 

[paulmd]

Is it the motherboard that will be damaged or the dell psu? The
motherboard would be bad news. But I'm not worried about the dell psu,
because I have more than one.

BOTH. Stop screwing with the dell power supplies. Get a real ATX.

I didn't see any smoke (or anything like that) coming from the
motherboard, so there is some hope left...

Many Dell PSU's do NOT follow the ATX wiring standard. Check the wires on
the old PSU against the ones on the DELL PSU. They don't have to be the same
colour wires, but the number of each colour wire and their positioning must
match.

I found an article about the issue [1]. And it seems possible to change
the wires to obtain a true ATX connector.

[1] http://www.quepublishing.com/articles/article.asp?p=339053&rl=1

it is, and you can buy one pre-done, too. But just find a real atx
power supply.

 

[Jef Driesen]

BOTH. Stop screwing with the dell power supplies. Get a real ATX.

I just tested the motherboard and it survived my mistake. If I had a
real ATX, I would use it, but that's not the case. And I don't want to
spend much money on old hardware.

I didn't see any smoke (or anything like that) coming from the
motherboard, so there is some hope left...

Many Dell PSU's do NOT follow the ATX wiring standard. Check the wires on
the old PSU against the ones on the DELL PSU. They don't have to be the same
colour wires, but the number of each colour wire and their positioning must
match.

I found an article about the issue [1]. And it seems possible to change
the wires to obtain a true ATX connector.

[1] http://www.quepublishing.com/articles/article.asp?p=339053&rl=1

it is, and you can buy one pre-done, too. But just find a real atx
power supply.

The pre-built converters I found on the net are for using an ATX psu
with a dell mainboard and not the other way around.

 

[kony]

I just tested the motherboard and it survived my mistake. If I had a
real ATX, I would use it, but that's not the case. And I don't want to
spend much money on old hardware.

You should be able to find a decent brand old ATX PSU of
about 250W for cheap, check some closeout/surplus
websites... Pricewatch used to sell Sparkle 250W for $15
delivered, they might've sold out of those at this point but
other deals about. Mainly what you should avoid is buying
one of the newer generics... an old 250-300W for $15 is
better than a new so-called 500W for $15 in most situations
(save for a rare sale/rebate/etc).

 

[DaveW]

The Dell PSU is too underopowered AND it is a PROPRIETARY PSU that only
works with Dell's PROPRIETARY motherboards due to odd connectors.

 

[philo]

One of my old PIII system (500 MHz if I remember correctly) suddenly
won't boot anymore. Sometimes I can get as far as the boot screen and
than stops abrupt (e.g. like when unplugging the power cable). But most
of the time it doesn't boot at all, and it remains completely dead.

I tested with the power supply unit (psu) from a similar system and
everything goes well again. So I tried to get my hands on a new psu. I
could recuperate one from a dell optiplex GX1 (also a PIII system).

If you want a free one (for the price of postage only) and are in the USA

I have a few spares in my basement 200 & 235 watt Dell

my gmail address is philo565

 

[kony]

The Dell PSU is too underopowered AND it is a PROPRIETARY PSU that only
works with Dell's PROPRIETARY motherboards due to odd connectors.

Those Dell PSU were pretty well made, a 200W should run a
typical early P3 system fine.

 

[Jef Driesen]

If you want a free one (for the price of postage only) and are in the USA

I have a few spares in my basement 200 & 235 watt Dell

Thanks for the offer, but I already have a Dell psu (I need a real ATX
one). And I live in Europe :-(

 

[paulmd]

I just tested the motherboard and it survived my mistake. If I had a
real ATX, I would use it, but that's not the case. And I don't want to
spend much money on old hardware.

Find an old Pentium 2, and steal it's power supply. You may even get
some more spare parts and/or upgrades out of the deal. Old machines
like these turn up in garage sales and yard sales everywhere.

 

[Jef Driesen]

Find an old Pentium 2, and steal it's power supply. You may even get
some more spare parts and/or upgrades out of the deal. Old machines
like these turn up in garage sales and yard sales everywhere.

That's exactly how I got those Dells ;-)

And I'm going to reuse some parts for an upgrade too (memory and
processor). I still have to find out how to remove the heatsink from the
dell processors (slot 1). The fan is mounted besides the heatsink
(probably not very effective) and does not fit very well in my case.

 

[philo]

).

Thanks for the offer, but I already have a Dell psu (I need a real ATX
one). And I live in Europe :-(

Darn! How am I ever going to get rid of those Dell supplies that I've been
hanging on to?

 

[paulmd]

That's exactly how I got those Dells ;-)

And I'm going to reuse some parts for an upgrade too (memory and
processor). I still have to find out how to remove the heatsink from the
dell processors (slot 1). The fan is mounted besides the heatsink
(probably not very effective) and does not fit very well in my case.

There are a couple ways of doing it, depending on the connection used.
The ones with a metal backing are easy enough. Slide the plate until it
releases (there's at least 6 variations on that theme, so i can't be
too specific). The ones with the plastic pins..... scary. There a
couple ways that work. Push the pins through (which is very hard). Or
gently pry out the whole heatsink with a flat, wide screwdriver. (I DID
say SCARY). This involves putting a metal tool directly on a circuit
board and applying force. And you CAN kill a perfectly good chip that
way. So its a delicate operation at best. Get one corner started, then
another, and another and repeat until it releases.

I've also seen metal rivets. You can't get those out short of a drill.

I think dell uses kind of a truss. it looks a bit like a railroad
bridge trestle. You can gently lever that out, but the part is easy to
snap in half, so watch it.

 

[paulmd]

).


Darn! How am I ever going to get rid of those Dell supplies that I've been
hanging on to?

Ebay. Craigs list. Freecycle. Thing is dell power supplies rarely die.

 

[w_tom]

The Dell PSU is too underopowered AND it is a PROPRIETARY PSU that only
works with Dell's PROPRIETARY motherboards due to odd connectors.

How many watts in a clone power supply? Some claim their 400 watt
supply is 575 watts. Are they lying? No. But you should have enough
basic electrical knowledge to understand why the Dell with a small
wattage number is as powerful as the larger clone supply AND why the
Dell's number is more relevant.

That Dell 200 watt supply would be rated by some clone manufacturers
at maybe 290 watts. That Dell supply would typically be sufficient for
a PIII system.

Brand name power supply are often accused by 'cloners' of being
undersized only because some cloners did not first learn basic
electrical concepts. Meanwhile some larger wattage power supplies are
also missing other 'industry standard' and essential functions that are
included in the Dell supply.

 

[Jef Driesen]

There are a couple ways of doing it, depending on the connection used.
The ones with a metal backing are easy enough. Slide the plate until it
releases (there's at least 6 variations on that theme, so i can't be
too specific). The ones with the plastic pins..... scary. There a
couple ways that work. Push the pins through (which is very hard). Or
gently pry out the whole heatsink with a flat, wide screwdriver. (I DID
say SCARY). This involves putting a metal tool directly on a circuit
board and applying force. And you CAN kill a perfectly good chip that
way. So its a delicate operation at best. Get one corner started, then
another, and another and repeat until it releases.

I've also seen metal rivets. You can't get those out short of a drill.

I think dell uses kind of a truss. it looks a bit like a railroad
bridge trestle. You can gently lever that out, but the part is easy to
snap in half, so watch it.

Mine is like the plastic "bridge" you describe. I found a picture on the
net [1]. Applying enough (actually it's quite a lot of) force releases
the plastic pins. I was a little afraid of damaging something, so I
tested on a spare one first, but it went just fine.

[1] http://www.roberthancock.com/dell/frankspics/STEP6new.jpg