Service manual

E8408A Product Specifications 63
Appendix A
Short-to-Other
Protection
A short-to-other output will generally cause a global shutdown. When the
fault is removed, the supplies will typically recover when the Power
On/Standby switch is cycled. However, if this switch is cycled while the fault
is still present, some supplies may become active or global shutdown may
occur again.
Conditions such as +5V-to-other output and -12V-to-(-5.2V) may cause a
shutdown that will not respond to cycling the Power On/Standby switch.
In this case, the Power On/Standby switch should be placed in Standby
position and AC power must be removed and reapplied before the
mainframe will turn on again.
Repair Diagnosis and troubleshooting through the front panel monitor ( MTTR =
Mean Time to Repair
).
Item Time
MTTR, power supply
assembly:
< 20 min (w/mainframe and modules fully
installed in rack)
MTTR, fan: < 30 min (w/mainframe and modules fully
installed in rack)