[c-nsp] C3500XL fans turn on, then turn off! For good!

[Tristan Gulyas]

All,

As per subject, I have a real mystery problem with a 3524XL-EN here.

a) I turn it on, and the fans don't come on.  After a few minutes, the fans 
will switch on for a minute or two, seemingly running at a higher speed than 
usual.  Then they will all switch off... and not come back on again until I 
pull the power on the switch.

b) If I replace the power after the switch has been running, the fans will 
come on straight away for about three seconds, then turn off.

If I leave it for a few hours and then plug it in again, it starts up as per 
a).

The unit gets mighty hot when the fans aren't running.

Any suggestions?  I've tried firmware updates and erasing flash but that 
hasn't helped.

.t