Service manual

8-6 11713A Operating and Service Manual
Servicing the Attenuator/Switch Driver
Troubleshooting
c. Verify that the pulse reaches the clock input of A3 latch assembly
driver assembly storage register flip-flops. Verify that the Q and
NQ outputs change state as the corresponding pushbutton is
exercised.
d. Measure input and output levels of inverting drivers on the A2
driver assembly.
e. If all logic levels up to the Darlington transistors operate, check
for shorted or open Darlington transistors. For proper operation
the voltage across the series base resistor to the Darlington
transistors should be greater than or equal to 0.5 Vdc when the
transistor is on.
8. To check the driver in remote operation with no external loads
connected, use an appropriate controller program to execute the
following commands.
NOTE The default address 728 is set at the factory. If you are using a different
address number, replace 728 in the commands above with the
appropriate address of your instrument. Refer to "GPIB Addressing".
Command Desired Outcome
REMOTE 728 The REMOTE light turns ON.
OUTPUT 728;"Al2345678" All attenuator lights go ON except the local
light.
OUTPUT 728;"Bl2345678" All attenuator lights go OFF except the remote
light.