roy@phri.UUCP (Roy Smith) (08/14/87)
We've been having problems with our new KFPS-2 crashing. At first
we suspected software (we're running KIP/CAP, after lots of you folks
debugged my config files for me; thanks!) but now it looks like power
supply problems which may be widespread (hence this note). We've got S/N
695; apparantly the problems are confined to a certain S/N range but I
don't know what it is. I also don't understand (and neither does tech
support) why our brand new KFPS-2 has that S/N since currently shipping
units have S/N's over 1000.
From what I gathered by talking to Kinetics tech support, on some
KFPS-2's, the power supply will start to drift if the kbox is on a DELNI.
On a xciever, the kbox supplies +5V to the xciever, but the DELNI has its
own power supply so doesn't draw any +5V current from the kbox. If I got
the story straight, this causes the +/-12V in the kbox to drift. This
sounds plausable, but I'm not a power supply guru.
Supposedly, putting the kbox on a xciever should make the problem
go away. In our case it just made it worse (we used an InterLan NT-100).
On the DELNI, the kbox crashed maybe once a day, on the NT-100, it was more
like every 15 minutes. Unfortunately, moving back to the DELNI didn't get
us back to once a day crashes, so I suspect the NT-100 did something to the
kbox.
BTW, by "crash" I mean the following. We would be running OK in
both directions (Ether-AT and AT-Ether) when everything would stop working.
Ping would show the kbox dead. Sometimes just doing a restart from
FastPath(tm) Manager would do the trick, sometimes it required a reload,
and sometimes the Manager wouldn't even see the box unless you cycled power
on it.
--
Roy Smith, {allegra,cmcl2,philabs}!phri!roy
System Administrator, Public Health Research Institute
455 First Avenue, New York, NY 10016cetron@CS.UTAH.EDU (Edward J Cetron) (08/15/87)
we had the same problem with our kfps-2's....tech support should be able to tell you how to remove the cover, and look at the manufacturer's name on the power supply. they can then tell you if it is the 'bad' one... they will replace them at no charge if it is the 'bad' one.... btw, our top EE looked at the power supply design (the bad one) and laughed hysterically...seems it is a very common design flaw which allows the supply to regulate properly only under load. -ed cetron@cs.utah.edu