Keithley 194 Instruction Manual page 203

MAINTENANCE
Table 7-9. Power Supply Checks
step Item/Component
Required Condition Remarks
1
5102 (Line voltage select) Set to 115 or 230V as required
Operate on correct line voltage.
2 Line fuse (FlOl) Continuity Check with ohmmeter.
3 Digital supply fuse (F102)
Continuity
Check with ohmmeter.
4 AC power Plugged into live receptacle,
power on.
5 VR104, pin 1
+25v, *20%
Referenced to VR104, pin 3
6 VR104, pin 2
+15v, *5% Referenced to VR104, pin 3
7 VR103, pin 2
-25V, +20% Referenced to VR104, pin 3
8 VR103, pin 3
-15v, *5% Referenced to VR104, pin 3
9 VR106, pin 1 +12V, *20%
Referenced to VR104, pin 3
10 VR106, pin 2 +5V, +5%
Referenced to VR104, pin 3
11 VR105, pin 2
-12v, *20% Referenced to VR104, pin 3
12 VRlO5, pin 3 -5V, *5% Referenced to VRlD4, pin 3
13 VR108, pin 1 +25V, *20% Referenced to VR108, pin 3
14 VR108, pin 2
+15v, *5%
Referenced to VR108, pin 3
15
VR107, pin 2 -25v, *20%
Referenced to VR108, pin 3
16 VR107, pin 3
-15v, *5% Referenced to VR108, pin 3
17 VRllO, pin 1
+lZV, f20% Referenced to VR108, pin 3
18 VRllO, pin 2
+5v, *5% Referenced to VR108, pin 3
19 VR109, pin 2 -lZV, +20% Referenced to VR108, pin 3
20 VRlOl, pin 1
+25V, f20% Referenced to digital common
(J102311024 pin 2 or 3)
21 JlD23, pin 1
+5v, *5% Referenced to digital common
22 VRlOl, pin 2 +15V, *5% Referenced to digital common
23 VR102, pin 3 -15V, *5% Referenced to digital common
24 U119, pin 14 +5v, *5% Referenced to digital common
25 U119, pin 8 and 11 Duty cycle varies with load.
32V
Jim
/-20@q
26 R108iTI02 junction Duty cycle varies with load.
30V
11
il.!--
I--20/m-/
7-30