Why Power Supply Died?

One of the factories I sell for had an old 286 PC a few years ago that
stayed on 24/7 for about 3 years (all it did was operate a bridge between an
ancient IBM card-based data collection system and an A/S400 computer). It
died one day, and I opened it up for them. It looked just like the inside of
a vacuum cleaner bag. Dust killed that one. On the positive side, we got
another old 386 computer at a yard sale for 5.00 and replaced it!
"w_tom" wrote in message
...
You already have the list of every time dust has caused
failures - including computers before PC existed. Dust
problems are myths often associated with a tech who is
'reaching' to solve a problem he never understood.

Fans don't fail due to dust. They fail due to internal
failures such as seized bearing, misplaced rotation sensor, or
failed transistor. Been doing this for too many decades to
fall for the 'too much dust' myth. No reason to use
compressed air on electronics. Dust may create a marginal
problem if ventilation holes are obstructed and computer
operates in a 100 degree F room. Even a soft paint brush
solves that problem.

Ben Myers wrote:
Let me know when the dust and dirt in your computer builds up
enough to cause a critical fan to stop spinning, with one or
more components burning up as a result... Ben Myers

Beats me what he was talking about. I buy cartons of "Blow Off" in small
quantities for my own use. I've also run into other brands with similar
product. Nothing but air. Nothing but net? Using this stuff is a slam-dunk
for me... Ben Myers

On Mon, 19 Apr 2004 09:39:47 -0400, "Prilosec" wrote:

Do you think he was talking about the industrial-type compressed air that
contains oil/water? I can see how that might be bad for electronics. The
junk in the can you buy at Staples is probably OK.
ben_myers_spam_me_not @ charter.net (Ben Myers) wrote in message
...
Hmm. Never ever had a problem with a computer getting into difficulty as
a
result of my blasting it out with compressed air. Must be either dumb
luck or
highly refined technique. Several dealers and resellers in my
neighborhood with
whom I have a loose arrangement to exchange parts and repair/maintenance
have
never had a problem either.

Admittedly a computer CAN survive with a lot of dust, dirt, dead mice, and
animal hair inside it. But the chances of survival are generally better
if the
interior is somewhat clean, allowing clear and unimpeded air flow.

I've also serviced a proprietary computer (a custom printer RIP) never
ever
cleaned by the so-called maintenance person. Opened up the chassis and
found a
ball about the side of a baseball consisting of cat hair, paper chaff,
dust,
dirt, and heaven knows what else. And that computer had a failed power
supply.
Luckily for my client, a common personal computer power supply fit right
in, so
there was no need for a service call from the other guy using parts paid
via
extortion.

Factory environments are especially hard on personal computers, and some
regular
cleaning out of the dirt prolongs the life of the machine.

That's my opinion, and you are just as free to have yours... Ben Myers

On Thu, 15 Apr 2004 17:03:21 -0400, w_tom wrote:

Compressed air can even change critical dip switch
settings. Never use compressed air on electronics. In on
case, a user vacuumed the computer and therefore removed a
jumper setting. Computer would not operate.

At most, gently vacuum or blow dust off of ventilation
holes. Nothing more. If a dust problem is that large, then
either an industrial grade computer for a harsh environment is
required, or some silly person installed too many fans. Five
fans inside a case does create dust problems especially since
most every computer works just fine with only one 80mm fan.

Why did power supply die? Air that is exhausted from
computer must not be air that reenters computer. Ventilation
is why holes must be properly cut in a cabinet that holds a
computer - so that heat does not recycle. Computers must work
just fine when room air is 100 degree F. A computer in a 70
degree room just will never have failures due to dust - if
computer is properly designed and ventilated.

Do not use compressed air on electronics. First it is not
necessary. Second it can cause other failures. Too many have
this 'clean' fetish. They always want to cure something only
because it looks dirty. Short of large globs of dust on
ventilation holes or large dust balls inside the case -
removing dust is unnecessary.

I only remove dust because I don't like getting my hands
dirty if I happen to be inside the machine. Once even found
a death mouse. But computer worked just fine.

"A. & C. Bredt" wrote:
I have it on a UPS, but I see that it is very dusty inside.

How often would you use compressed air to clean it? Should I open
it each time to do it?

I've cleaned some fan fins that had caked dust/lint/hair on them to the
point that they added a small beaded effect to the edge of the fan. Now I'm
no ventilation/fan expert but I would think that the added weight of all
that crud would accelerate the demise of that fan. Also wouldn't those
altered fan blade edges alter the efficiency of the fan? Fan outages can
indeed croak a system, CPU or component.

In the systems I've seen, the motherboard is usually mounted vertically and
thus doesn't tend to be a dust collection point. Other components and areas
tend to gather dust/hair/crud and I can't see that they'd be very
susceptible to a short blast of compressed air.


"w_tom" wrote in message
...
You already have the list of every time dust has caused
failures - including computers before PC existed. Dust
problems are myths often associated with a tech who is
'reaching' to solve a problem he never understood.

Fans don't fail due to dust. They fail due to internal
failures such as seized bearing, misplaced rotation sensor, or
failed transistor. Been doing this for too many decades to
fall for the 'too much dust' myth. No reason to use
compressed air on electronics. Dust may create a marginal
problem if ventilation holes are obstructed and computer
operates in a 100 degree F room. Even a soft paint brush
solves that problem.

Ben Myers wrote:
Let me know when the dust and dirt in your computer builds up
enough to cause a critical fan to stop spinning, with one or
more components burning up as a result... Ben Myers

Two fan problems involve bearing wear and location of the
hall effect sensor. Bearing wear creates far more stress on
fan. The hall effect sensor, if not perfectly flat on printed
circuit board (inside fan) can create insufficient torque (fan
stalls). These are manufacturing defects. Dust on fan blades
is not significant. In fact, if dust was significant, then
fan was defective when it left the factory.

If fan suffers an early demise, then suspect power supply
manufacturer or computer assembler is again selecting
components only on price - quality and manufacturer integrity
be damned.

One reason why some clone assembler recommend annual
cleaning - they install too many fans. One 80 mm fan is
typically enough cooling for most every computer. Too many
case fans create significant dust buildup problems. Do the
numbers. Theoretical numbers confirmed by experimentation
says the computer works just fine even in a 100 degree F
room. Too many fans create dust problems.

snoopy wrote:
I've cleaned some fan fins that had caked dust/lint/hair on them
to the point that they added a small beaded effect to the edge
of the fan. Now I'm no ventilation/fan expert but I would think
that the added weight of all that crud would accelerate the
demise of that fan. Also wouldn't those altered fan blade edges
alter the efficiency of the fan? Fan outages can
indeed croak a system, CPU or component.

In the systems I've seen, the motherboard is usually mounted
vertically and thus doesn't tend to be a dust collection point.
Other components and areas tend to gather dust/hair/crud and
I can't see that they'd be very susceptible to a short blast
of compressed air.