Service manual

28 Troubleshooting
TURN OFF SUPPLY AND REMOVE THE TOP COVER
AND RFI SHIELD. DISCONNECT LOAD. CONNECT
SENSE TERMINALS FOR LOCAL SENSING.
START
"OVERALL TROUBLESHOOTING"
TURN ON SUPPLY AND CHECK FOR INDICATION
(FAN RUNNING, DISPLAY ON, DC RAIL LED DS420,
DS421 ON) THAT AC POWER IS ON.
CHECK FOR AC POWER ON A4 BOARD. CHECK
F800 AND CHECK FOR 24 V BIAS ON A6 BOARD.
CHECK AC LINE SWITCH A1S1.
IS
FAN RUNNING ?
GO TO NO DISPLAY TROUBLESHOOTING FIG. 3-2
IS
DISPLAY
ON?
ERROR
MESSAGE
DISPLAYED?
SEE SELF TEST ERROR CODES, TABLE 3-2
WITH FRONT PANEL KEYS, PROGRAM FULL SCALE
VOLTAGE AND CURRENT (SEE TABLE 2-2). USE DVM
TO MEASURE VOLTAGE AT OUTPUT TERMINALS.
OUTPUT
VOLTAGE WITHIN
SPEC?
VOLTAGE
RIGHT BUT OUT-
OF SPEC?
CALIBRATE THE SUPPLY
NO
YES
YES
NO
YES
NO
YES
NO
YES
A
GO TO SHEET 2
GO TO SHEET 4
B
YES
NO
PERFORM CHECKS IN OPERATING
MANUALS,
DID YOU DO
TROUBLE SHOOTING IN
PAGE 3-5 IN OPERATING
NO
YES
YES
MANUAL ?
Figure 3-1. Overall Troubleshooting (Sheet 1 of 4)