Keithley 2015 - Power Supply Checks

Troubleshooting 4-19
Power supply checks
Power supply problems can be checked out using Table 4-3.
Table 4-3
Power supply checks
Step Item/component Required condition Remarks
1
2
3
4
5
6
7
8
9
10
11
12
Line fuse
Line voltage
Line power
U144, pin 2
U101, pin 7
U125, pin 3
U119, pin 3
U124, pin 3
U331, pin 2
U348, pin 3
U349, pin 3
U350, pin 3
Check continuity.
120V/240V as required.
Plugged into live receptacle,
power on.
+5V ±5%
+37V ±5%
+15V ±5%
-15V ±5%
+5V ±5%
+5V, ±3%
+15V, ±5%
-15V, ±5%
+5V, ±5%
Remove to check.
Check power module position.
Check for correct power-up
sequence.
+5VD, referenced to Common D.
+37V, referenced to Common D.
+15V, referenced to Common A.
-15V, referenced to Common A.
+5VRL, referenced to Common A.
+5VD2, referenced to Common D.
+15VA, referenced to Common F.
-15VA, referenced to Common F.
+5VA, referenced to Common F.