Power Supply Checks - Keithley 2015 Service Manual

Power supply checks

Power supply problems can be checked out using Table 4-3.
Table 4-3

Power supply checks

Step Item/component
1 Line fuse
2 Line voltage
3 Line power
U144, pin 2
4
U101, pin 7
5
U125, pin 3
6
U119, pin 3
7
U124, pin 3
8
U331, pin 2
9
U348, pin 3
10
U349, pin 3
11
U350, pin 3
12
Required condition
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%
Troubleshooting
Remarks
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.
4-19