Advice on a PeeCee

[mikeymike]

The floppy light never comes on, even with the Win95 boot floppy in it (have that thankfully).

That could just be because floppy boot and seek are disabled.

So when you switch the machine on, exactly what happens?  Display?  Keyboard light flash?  Any beeps?

[mikeymike]

JaXanim wrote:
@mikeymike
Other than the power-on LED, there are no lights at any time. Not from the keyboard or floppy drive. The floppy drive was working before I got the machine. And there are no beeps either. There is no display output on the monitor which came with it.
Other than the HD spinning, the thing seems dead. Remember I fitted a new ATX box to replace the original, which had blown out at least two capacitors. That event probably killed the mobo, eh?
Cheers,
JaX

No CPU fan either?

Try removing everything (CPU, RAM, graphics etc) except the case connection for the switch and obviously the PSU connection.  The system should beep (I can't remember what sequence of beeps) at you.  Then progressively put the rest in on each success.

Old ATX motherboards are temperamental.  Sometimes for "no apparent reason", they stop booting, and just removing and reinserting fixes the problem.

[mikeymike]

JaXanim wrote:
@Mikeymike
Yes there's a fan, but it's never been connected to any power.

The CPU fan has never been connected?  What is the CPU?  It would have to be a 486 or a huuuuuge heatsink or a very good PSU to handle the heat from the CPU.

OK, I'll try your suggestion. Maybe if it works, I can use the mobo as a doorbell?

Consider that you might have to 'coax' it into working :-)  Use the PSU power switch (if there is one), then pull the power out the back of the PSU, reconnect stuff, put power back in.  Try as many combinations as you can think of.

You should get beeps to tell you the following:
* Boot OK (single short beep)
* beeeeep beep beep beep (graphics missing)
* varying sorts of beeps to signify lack of RAM/CPU

If you can't get any beeps at all with no hardware around at all, then start thinking the machine is a doorstop.

Try connecting the PC speaker the other way round as well (temporarily, if it doesn't work).

Try disconnecting and reconnecting the battery also.
  (adding to other suggestions already made)

[mikeymike]

The heatsink with fan attached was clipped to the CPU OK, but the power lead from the fan was rolled up with a rubber band around it. The plug had never been connected to the supply. This is definitely the condition as originally purchased. Would that be likely to eventually fry the CPU?

Eventually?  It could fry a 486 unless it had a very modern heatsink.

AMD K6-2s don't run very hot (relative to other x86 CPUs), but if you run one for ten seconds without a heatsink from cold, the CPU will be hand-warm.  They do need fans.  I have a K6-2 450 @ 550MHz, and the heatsink/fan is just about hand-warm after a few hours of normal operation.

I wonder what 'very light use' means.  If the machine were kept somewhere cool (ie. a cool breeze could get into it), then it would probably protect the CPU enough.  My guess is, that machine crashed quite often.  With a couple of other lucky factors, it may have saved the CPU from being damaged.

[mikeymike]

The K6-2 300 would put it around 1998-99 IIRC.  95/96 were the days of ~100MHz.  I remember getting a P133 machine (which was about midrange then) in mid to late '96.

As for the CPU fan not being connected - does it look like there's any chance the fan might have been connected but somehow came out of the socket?  I'm clasping at straws here, because I simply don't believe anyone would be quite stupid enough to unplug it :-)

As for the 'signs of tampering', I wonder whether someone was planning on scrapping it for parts, like maybe a card was in it but now has been removed.

[mikeymike]

One other thing, is any dust collected in strange patterns in the heatsink?

- edit - also, is the amount of dust on the heatsink about the same as on the motherboard / inside the case generally?

[mikeymike]

Not quite :-)  If there is a circular dust pattern on the heatsink, usually along with dust clogging up the heatsink in a consistent pattern, then the fan has been running on it at some point in its life.

If the dust is spread around the heatsink as if it were any other unventilated surface, then the fan hasn't been running on it.

If there is less dust on the heatsink than on the rest of the machine's insides, then the heatsink/fan has probably been swapped out at some point.