O.T. Dell 8200 cannot power up

I of course meant didn't.

Robert

On Monday, December 14, 2015 at 9:35:56 PM UTC-8, Mark Twain wrote:
You know what, I kind of thought I
had taken out the 8200 power supply
before.

Now I remember, I did, to grease the
fan bearing with with white lithium
grease.



Of course, I didn't unplug the power
supply when I did this.

Robert

Mark Twain wrote:
I opened up the 8200 and did see
anything like you described:

http://i65.tinypic.com/1zdpvu9.jpg

http://i64.tinypic.com/jsh6di.jpg

rOBERT

All I see in the upper right corner of the
board is the 20 pin main connector. And some
nylon ties holding a lot of stuff together.

I don't see a 1x6 AUX connector up there,
so maybe this design doesn't use or need one.

You have tall electrolytic caps on either
side of a toroidal coil in the upper right
hand corner. One of the caps (the one on the
left) is tilted at an angle. That might be
a stuffing error when the board was new.
Or, the rubber plug in the bottom of the
electrolytic capacitor could be pushing
out (from internal gas pressure). Look for
a orange-brown stain on the motherboard surface
around that electrolytic, if the thing is
actually leaking. Sometimes the pressure relief
seam on top doesn't break open, and instead
the rubber plug in the bottom pushes out to relieve
pressure. And this can cause the electrolytic
to stand tilted on the motherboard.

The layout of the machine is fairly open, so it should
not be hard to get the supply out of there. But the
usage of nylon ties, a nylon cable holder
on the bottom of the supply, will be a slight
nuisance when working on it. As long as you keep
your reference pictures (like you've done), and
store those pictures on the 8500, you can use the
pictures for referral purposes when putting
the 8200 back together again.

Sometimes, when you get a new supply, the wire loom
isn't long enough. That's particularly a problem
for a scissor case, as it may not allow the case to be
opened up all the way, without straining the wires.
So when Startech says the supply is "compatible",
I hope they really mean it, cable length and all.

I keep a few bags of nylon ties here, and the
small ones come in handy for cable dress. Don't
over-tighten them to the point that they cut into
the wire insulation, if you decide to use those
to keep the wires tidy. Some supplies, the cables
are already dressed on the outside, so you won't
need quite as many nylon ties to do the job. A
bag of 100, will last forever :-)

Paul

So which power supply do I buy?

It doesn't look like there's any
orange/brown stain;

http://i65.tinypic.com/246116s.jpg

http://i63.tinypic.com/314b7lk.jpg

I would have noticed something like
that however now that you brought it
to my attention, the electrolytic cap
on the left is tilted backwards quite
a bit. So even if not leaking is this
is cause for concern?

http://i65.tinypic.com/v49kwi.jpg

I have thought of using zip ties but
the 8200 already has allot of the cables
holders already in place and it's just a
matter of using them.

I have thought of disconnecting the
cable from the front 1.0 USB ports since
I don't use it anymore and would clean
up the inside of the 8200 leaving only 2
ribbon connectors. My only reservation
is disconnecting it from the motherboard,
and how iffy is that?

Thoughts/suggestions?
Robert

I forgot to add that after opening
the 8200 up to take pictures and
then reconnecting everything the
amber power light and green drive
light did not come on when I powered
everything back up.

Robert

I was just thinking ,..... since
there's no orange/brown stain on
the motherboard that I can see
maybe when I dropped the pliers
it bent the electrolytic cap
backwards?

Robert

Mark Twain wrote:
I forgot to add that after opening
the 8200 up to take pictures and
then reconnecting everything the
amber power light and green drive
light did not come on when I powered
everything back up.

Robert


So something is making an intermittent
connection in there.

When I look at the third of your pictures,
there is a clip that holds the black
Northbridge heatsink to the motherboard.
Is that clip secure ?

There are four "hook-eyes" soldered
into the motherboard. I see one metal
bar with arms on either end, and the
arms fit into the hook-eyes. The
metal bar is under tension and holds
the heatsink down onto the Northbridge.
Sometimes those hook-eyes pull out
of the motherboard. I don't see a reason
to panic there, but from the camera
angle, I can't tell if the lower arm
is properly in place or not. The reason
for four hook-eyes, is the original
Intel design used two metal arms which
would cross over one another, but manufacturers
only installed one of the arms.

And on one Dell design, there is a continuity
check across that arm. The motherboard puts
a tiny bit of current through the arm, to detect
the arm is in place. You don't have any symptoms
to suggest that scheme is in place - if the arm
is disconnected, sometimes it causes the
computer to just fail to start. As when the
"arm-detector" circuit is in place, it is
wired into the start circuit, such that the
computer cannot start unless the arm is
fastened to the hook-eyes on either end.

Your electrolytic capacitor looks fine, in
terms of external visual symptoms. I don't
see any leakage. When capacitors get installed,
the "span" of the leads doesn't always match
the hole pitch on the board, so the capacitor
doesn't always end up snug and flush to the
motherboard. So there's no reason to panic
from that point of view. It's OK for it to be
at an angle like that. Just resist the urge
to go bending the thing, because you can
separate the bond of the leg to the capacitor
body inside, with enough effort.

The only reason I wanted you to look at that,
was in case internal pressure was causing
it to tip over. And there would be an
accompanying stain on the motherboard if
that was the case, and I don't see anything
there on the motherboard to support that
theory.

I don't know what to tell you at this point.
Either the problem is on the motherboard
end or the power supply end, but I just
can't tell from what I'm seeing.

If you want to disconnect the front panel
USB, disconnecting it at the motherboard
end would be the safest. On my motherboards
here, the connector would be a 2x5 with one
pin missing, and the missing pin is used for
"keying". That's so when you plug it in, you
get some hint which pin is the correct pin 1.

Paul

I assumed the erratic behavior was due
to a faulty power supply?

I opened it up again to get you
pictures of the clip and a close-up
of the electrolytic capacitor.

http://i63.tinypic.com/124v885.jpg

http://i66.tinypic.com/6qd3ba.jpg

Since there's no stains on the
motherboard and the clip is secure
I opt for a new power supply. As I
said it's already 15 years old.

Robert

"Mark Twain" wrote in message
...

So which power supply do I buy?

Do you use a specialist computer store (unlike a big
box store)? My experience (twice over the years)
has been that when I took a nonstarting PC into a
specialist store, and bought a new PSU, it was
installed at the counter with no charge. It is that
quick and easy, with only three or four connectors
to plug in.
--
Don Phillipson
Carlsbad Springs
(Ottawa, Canada)

Mark Twain wrote:
I assumed the erratic behavior was due
to a faulty power supply?

I opened it up again to get you
pictures of the clip and a close-up
of the electrolytic capacitor.

http://i63.tinypic.com/124v885.jpg

http://i66.tinypic.com/6qd3ba.jpg

Since there's no stains on the
motherboard and the clip is secure
I opt for a new power supply. As I
said it's already 15 years old.

Robert

We haven't proven at this point, that
it is the power supply. Purchasing a
replacement power supply and installing it,
might achieve nothing.

So it's a gamble.

Compare this gamble, to the cost of a
"diagnose" at a local computer store. For example,
one store in town charges "$99 to look at it".
Maybe where you live, they will do it for less.

Paul

We have no local computer store.

If I can't do here then its not
going to get done.

Robert

Another reason for purchasing a
power supply is that as you pointed
out they are getting harder to find
and as I pointed out it's already
lasted 15 years. It's time for a new
one.

Robert

Also 'if' there were a computer store;
buying a new power supply is a far cheaper
gamble than paying someone $99 'just to check
it out'. I would rather gamble with the'
power supply plus you never know how reputable
any given computer repair place may or may not
be.

Robert

There is no computer store in my area
and I can install a power supply.

Thanks,
Robert

Also, did you not say that if
it's not the power supply it
must be the motherboard?

I'm weighing all the options
and it seems to me that buying
a power supply is a logical choice
because we've tried everything else
and there was no problems previously.

If it's the motherboard that's
another discussion entirely.

Robert