22 Jun
2000
22 Jun
'00
3:02 a.m.
On June 21, Tony Duell wrote:
Power Supply Margin testing, I guess. Basically it runs the PSU (+5V
line, probably) at 5% over or under the 'right' value. If you have an
intermittant fault to trace, this may make it appear permanently so you
can track it down. Similarly, a machine that fails on either of the
margin settings is likely to _become_ unreliable even at the normal
voltage, so you can catch errors during preventive maintenance.
Interestingly, both the Cray J90 and the YMP-EL (and possibly other
models as well) have +- margin switches for their power regulators
accessible on their front panels.
-Dave McGuire
ps margin: +5%/normal/-5%
What's a ps margin switch for?