Service manual

38 Troubleshooting
YES
NO
START
WARNING:
SUPPLY
OPERATES
PROPERLY?
"SERIAL DOWN"
TURN OFF SUPPLY, REMOVE TOP COVER AND RFI SHIELD.
UNPLUG CABLE W5 FROM J108 ON A2 GPIB BOARD AND
PLUG CABLE W5 INTO J507 ON A10 BOARD (SEE WARNING).
THIS REMOVES THE GPIB BOARD
FROM THE DATA PATH AND CONNECTS THE
FRONT PANEL DIRECTLY TO THE CONTROL BOARD.
THIS CONFIGURATION IS FOR TEST ONLY. DO NOT
FLOAT THE OUTPUT OR ATTEMPT TO OPERATE
OPERATE THE SUPPLY IN THIS CONFIGURATION.
TURN OFF SUPPLY. REMOVE FRONT PANEL
ASSEMBLY TO ACCESS THE A1 FRONT PANEL
BOARD. TURN ON SUPPLY AND CHECK FOR
PULSES AT A1U3-17 AND A1U3-18 .
PULSES
AT A1U3-17? CHECK CABLE W5.
PULSES
AT A1U3-18?
YES
NO
YES
NO
TURN ON THE SUPPLY AND TRY TO PROGRAM IT FROM THE
PROBABLE DEFECTIVE A2 BOARD
PROBABLE DEFECTIVE
A1 BOARD
UNPLUG CABLE W4 FROM J507 ON A10 CONTROL BOARD.
FRONT PANEL.
Figure 3-8. Serial Down Troubleshooting)