computer power supplies..

[Bob Larter]

Not a bad idea.

Remember the Full Height 5 1/4's ? They took about 30-40 W.

I used to own several ST-506s & ST-412s. Long gone now, of course.

 

[Powermac]

I used to own several ST-506s & ST-412s. Long gone now, of course.

--

I still have a few Seagate 9GB 5.25" FH SCSI drives in external boxes
for my old AVID capture setups. I keep them around because they still
work and are OEM to the systems.

The problem I see with most PS supplies are cheap parts that fail when
the fans cooling them get clogged up with cig smoke or pet hair, dust,
etc. That and buying one that is too small for the load you are
applying.

How did DELL and eMachines get away with small 250W max rated supplies
in P4 3Ghz+ and Athlon 64 3000+ systems? if you added a decent gaming
video card and an extra HD you probably had voltage issues.

 

[William R. Walsh]

Hi!

How did DELL and eMachines get away with small 250W max
rated supplies in P4 3Ghz+ and Athlon 64 3000+ systems?

Dell underrates their power supplies *greatly*. I've never had a
problem with one, and they seem to be pretty well made, in line with
other quality brands.

As an example, the 305-watt rated unit (made by Lite-On) in my
Dimension 8300 is powering two hard drives, 2GB of installed RAM, an
ATI Radeon X1350, two optical drives, floppy drive and a full host of
PCI expansion cards. It has no problems, and has been doing that since
it was new. The air coming out of it is moderately warm.

At first it powered a 3.4GHz P4 Prescott which ran distributed.net
around the clock. Later, I switched to a 2.8GHz Northwood as the
Prescott was good only for putting out heat sufficient to warm a small
country.

The eMachines supplies have two things working against them--the first
being that in some cases they don't have working overvoltage
protection in place. This results in motherboards getting fried. I
haven't seen too many that I could say failed as result of running out
of capacity anyway.

And you could do worse, with a supply that lies about its
capabilities:
http://greyghost.mooo.com/psuthoughts/

William

 

[Bob Larter]

I still have a few Seagate 9GB 5.25" FH SCSI drives in external boxes
for my old AVID capture setups. I keep them around because they still
work and are OEM to the systems.

Hard disks last a very long time if you're careful to give them enough
airflow to stay cool.

The problem I see with most PS supplies are cheap parts that fail when
the fans cooling them get clogged up with cig smoke or pet hair, dust,
etc. That and buying one that is too small for the load you are
applying.
Ayup.

How did DELL and eMachines get away with small 250W max rated supplies
in P4 3Ghz+ and Athlon 64 3000+ systems? if you added a decent gaming
video card and an extra HD you probably had voltage issues.

But most people don't do that.

 

[Baron]

I have to add "Me Too" I have a genuine Apple ST405 from 1982. Four
platter linear actuator. I don't remember how big it was, 10Mb maybe !

I still have a few Seagate 9GB 5.25" FH SCSI drives in external boxes
for my old AVID capture setups. I keep them around because they still
work and are OEM to the systems.

The problem I see with most PS supplies are cheap parts that fail when
the fans cooling them get clogged up with cig smoke or pet hair, dust,
etc. That and buying one that is too small for the load you are
applying.

I agree. Pay cheap, Get cheap !

How did DELL and eMachines get away with small 250W max rated supplies
in P4 3Ghz+ and Athlon 64 3000+ systems? if you added a decent gaming
video card and an extra HD you probably had voltage issues.

I'm sure that was quite deliberate ! Remember the "Warranty Void" if
you opened the case. Often enforced by a sticker over the removable
case panels. Huge numbers of people caused damage by fitting extra
drives, video cards and CD/DVD burners without understanding what they
were doing. Like everything else today... Pared down to the bone to
cut costs !

 

[westom]

How did DELL and eMachines get away with small 250W max rated supplies
in P4 3Ghz+ and Athlon 64 3000+ systems? if you added a decent gaming
video card and an extra HD you probably had voltage issues.

Learn what engineers know and what many computer assemblers don't
grasp. That 250 watt supply in a Dell is also called 360 watts when
sold to computer assemblers. Neither lied. Only one is providing a
more honest number. Latter is selling to A+ Certified Computer techs
who need not even know how electricity works to be certified.

Lack of technical knowledge is why so many power supply myths are
believed by a majority. Other popular myths involve thermal compound,
hardware damage due to heat, protectors, and shotgunning. Myths
traceable to untrained computer assemblers. So many as to suggest why
so much electronic and computer design must go overseas AND why so
many engineers (probably a majority) in the Silicon Valley are now
immigrants.

A choice is offered. To know only because the majority promote that
myth. Or to know by also learning why – which means numbers and the
underlying reasons why.

Dell does not underrate their supplies. Overrated is technical
knowledge of people who never first learned basic electrical
principles and then post as if knowledgeable. That has even created a
market ripe with power supplies that are missing essential functions.
They are selling to the electrically naive. But then this should be
obvious. If he does not provide the many technical reasons why - and
numbers - then assume myths.

 

[Eeyore]

I still have a few Seagate 9GB 5.25" FH SCSI drives in external boxes
for my old AVID capture setups. I keep them around because they still
work and are OEM to the systems.

Unfortunately we had Micropolis 9 GB drives for Lightworks that had a fatal
manufacturing error that consigned them all to scrap after a year or two.

The problem I see with most PS supplies are cheap parts that fail when
the fans cooling them get clogged up with cig smoke or pet hair, dust,
etc. That and buying one that is too small for the load you are
applying.

I have one ancient PC ( my old DOS box ) I've replaced the fan in twice.
Bearing failure, nothing else.

How did DELL and eMachines get away with small 250W max rated supplies
in P4 3Ghz+ and Athlon 64 3000+ systems? if you added a decent gaming
video card and an extra HD you probably had voltage issues.

Probably because they are *real* watts. The Asian ones are somewhat
optimistic.

Graham

 

[Eeyore]

I have to add "Me Too" I have a genuine Apple ST405 from 1982. Four
platter linear actuator. I don't remember how big it was, 10Mb maybe !

5MB unformatted. That's where the 5 in 405 comes from. 5 was the form factor
- F/H 5 1/4".

Graham

 

[Franc Zabkar]

The eMachines supplies have two things working against them--the first
being that in some cases they don't have working overvoltage
protection in place. This results in motherboards getting fried. I
haven't seen too many that I could say failed as result of running out
of capacity anyway.

And you could do worse, with a supply that lies about its
capabilities:
http://greyghost.mooo.com/psuthoughts/

I have a fake ATX PSU labelled as 400W, yet the Schottky rectifiers on
the secondary side can only deliver 200W max. Although it's still
working, I replaced it because the +5V and +12V rails were moving
about too much during load changes, eg when my CPU cooler program
kicked in.

- Franc Zabkar

 

[Adrian C]

Dell does not underrate their supplies. Overrated is technical
knowledge of people who never first learned basic electrical
principles and then post as if knowledgeable.

Westom = troll. Please ignore the patronising ramblings of this idiot.

 

[Baron]

5MB unformatted. That's where the 5 in 405 comes from. 5 was the form
factor
- F/H 5 1/4".

Graham

Thanks. Its a real dinosaur by todays standards.

 

[westom]

Please ignore the patronising ramblings of this idiot.

If the technicals were wrong, the poster would have challenged the
facts. Those who cannot attack the messenger. IOW Adrian is
declaring he does not have sufficient knowledge to disagree.

A 250 watt Dell supply may be sold to the technically naive as a 360
watts supply. Neither number is wrong. Others who also have this
rumored 'underrated' supply aslo had no power problems. Only the
naive would post without technical facts. And that is only when I
start posting - the challenge the technically naive to demonstrate
'why' they know. Adrian could not probably for good (under educated)
reason - an insult he earned by replying without facts and numbers.

 

[ZACK`]

Is there a group for repairing computer power supplies?..
Question... I have the power supply out of the computer...
Besides pluging it in... how do you turn it 'on'...
The front panel on / off switch connects to the mother board..
How can I turn the power supply 'on' at the power supply?...
Larry

to test them i use a PC/SPS TESTER
just plug the 20/24 pin connecter in and
plug in the power, leds idicate health of
supply.

 

[westom]

to test them i use a PC/SPS TESTER
just plug the 20/24 pin connecter in and
plug in the power, leds idicate health of
supply.

Tester can identify a defective supply. But it obviously cannot
report a good supply. Ciritical to testing a supply are voltage
numbers when supply is under maximum load. Tester can provide that
load and provides no numbers.