[rescue] Sun E450 - 'CPU Fan 2 Failure' but not failed

[microcode at zoho.com]

On Sun, Nov 10, 2013 at 01:37:37AM -0500, Greg Jurman wrote:
> On Sun, Nov 10, 2013 at 1:15 AM,  <microcode at zoho.com> wrote:
> > On Sun, Nov 10, 2013 at 12:51:08AM -0500, Greg Jurman wrote:

> So to see if there was a fault I spliced the fan connections around
> and swaped the wiring of Fan 1 with Fan 2. If it was the fan, the
> fault should of moved and it didn't. The fans don't send tach like a
> normal CPU fan, but rotor locked/stall (high if stalled, low if
> spinning). Grounding that signal line directly also didn't work.
> O-scope didn't show any problems with voltages or show any signal
> anomalies.

Sounds like you're checking pretty thoroughly and know what you're doing.
There may be some good news here, there's always the possibility that 
it's an OBP/LOM issue. Reading comp.unix.solaris and various mailing lists
for a few years now I have seen numerous "this can't be happening" hardware
problems "solved" by upgrading the OBP/LOM/ALOM levels. It would definitely
be a good idea to try to reflash before going any further on a mainboard
replacement. Mainboards are often more expensive than a whole new server,
especially if you live in a place where people are dumping/selling older
gear. The firmware is no longer publicly available, but since your box is
older somebody may still have the firmware from the Sun days.