"The Natural Philosopher" wrote in message
...
Suz wrote:

Sadly its back again, tho much less annoying and I think I may have
damaged the Pentium III beyond repair..I think the timing has driufted
somewhere and teh chip is getting stick in an interrupt service routine
sometimes.


A couple of things spring to mind.
Not the mouse, as it happens with more than one. Not the optical
sensors as
double clicks are being activated.


Yes. Beebn down that route as well.


Maybe a faulty mouse port? Try a serial mouse, USB mouse - one
different to
current one.


Tried a new mourse
Not that.


A stuck key (or 2) on the keyboard. Have seen this more than once. Alt
stuck on mine, and I caught on when pressing F4 as it tried to close the
program or tab shifted to another one.


No. Happens randomly when nothing else is going on. Rebbot (hard) always
fixes it, so cannot be stuick key. Ctrl Alt Del doesn';t work at all,
neither does any key - e.g. NuimLock - cause any keyboard light to
change state. The amount of hardware and software involved in e.g.
getting a keybaord light to change state is very small - probably
tehkeyboard, teh UART and a timney code fragment invoked under interrupt.

Its definitely UART, processor or memory.


Does it only happen when you are working on it, or does it happen when
you
aren't touching it? If it happens when you aren't touching it then I'd
look
at the mouse port, otherwise the stuck keys.



Seems to be that using the mouse makes it happen NOW, post getting fan
working.

Its entirely consistent with processor getting stuck in mouse interrupt
service routine. Sometimes removing mouse and re-inserting works,
sometimes nothing works.

Its possible i have a corrupted disk but I doubnt it. My giess is that
teh interrup part of the chipset has gone off the edge of its timing
somehow, and/or the UART is faling to respond correctly,


It's always a good idea to
give the keyboard a clean anyway, but if it isn't dirt, just sticky keys
then a good sharp stabbing on the usual offenders may help. Alt -esp if
windows are closing, but also Ctrl, arrow keys, Backspace, tab, shift.
Do
you have accessibilty options switched on, which allow keys to control
mouse
movements and if one key is stuck may generate the movements etc. Or an
alternative KB if you have one lying about.

If the kb is really bogging a good scrub with with soapy water is all
else
fails. Just don't put it up against the radiator to dry out, as a
colleague
of hubby's did. Went limp and he ended up with a banana shaped KB.

PS what makes you think its getting stuck in an interrupt service
routine?
Thats not easy to diagnose.


20 years as a hardware engineer and ten as a real time software engineer?

Bet you remember punched card stuff. ¦^)))