HP 2040D - Manual (Page 32)

Series 2040 Test System
Series 2040 Maintenance Manual V2.00 Diagnostics
31
TESTHEAD - PATCHBOARD - UUT P/S BUILT-IN DIAGNOSTICS
When a malfunction is suspected in either the Testhead Internal or
Patchboard Power Supply system, the LED status indicators should be
examined. The top LEDs are labeled for their respective power supplies as
shown on page 14. The legend for the four lower LEDs is shown below. In
case of a power supply malfunction, the power supply that has shut down first
will be indicated by its respective LED being extinguished.
If you are diagnosing the case of no power at the Patchboard, and the status
indicators, the lower four LEDs, are all lit, then an over/under voltage fault has
occurred in a Patchboard power supply. The power supply causing the fault
will have it’s respective LED extinguished. Power could also have been
removed from the Patchboard without generating a fault condition. In this
case, the reason that the power has been removed is indicated by one or two
of the lower four status LEDs being extinguished.
CASE PROX PBON Ext.Fault Reset
Power Call on off on on
TCLEAR on off on off
Patchboard removed off on on on
UUT Power Fault on on off on
When a power supply cannot be restored by resetting the unit, the circuit
breaker for the offending supply should be checked for continuity. A graphic of
the circuit breakers on the edge of the Testhead Power Supply Controller
board is shown on page 14 of this section. If any of these breakers continually
trips, the associated power supply must be replaced.