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Troubleshooting
4-11
Power supply checks
Power supply problems can be checked out using
. See “Principles of operation”
for circuit theory on the power supply.
Table 4-2
Power supply checks
Step Item/component* Required condition
Remarks
0
1
0
2
0
3
0
4
0
5
0
6
0
7
0
8
0
9
10
11
12
13
14
15
16
Line fuse
Line power
+5VDA TP
+5VA TP
-15VA TP
+5VA TP
-5VA TP
+110VA TP
-110VA TP
+5VDB TP
+5VB TP
-15VB TP
+5VB TP
-5VB TP
+110VB TP
-110VB TP
Check continuity.
Plugged into live receptacle, power on.
+5V, ±5%
+15V ±5%
-15V, ±5%
+5V, ±5%
-5V, ±5%
+110V, ±20%
-110V, ±20%
+5V, ±5%
+15V ±5%
-15V, ±5%
+5V, ±5%
-5V, ±5%
+110V, ±20%
-110V, ±20%
Remove to check.
Check for correct power-up sequence.
Referenced to GND DA TP.
Referenced to GND A TP.
Referenced to GND A TP.
Referenced to GND A TP.
Referenced to GND A TP.
Referenced to GND A TP.
Referenced to GND A TP.
Referenced to GND DB TP.
Referenced to GND B TP.
Referenced to GND B TP.
Referenced to GND B TP
Referenced to GND B TP.
Referenced to GND B TP.
Referenced to GND B TP.
*Test points (TP) are marked on circuit board.
Summary of Contents for 2500
Page 2: ...Contains Calibrating and Servicing Information Model 2500 Dual Photodiode Meter Service Manual...
Page 11: ......
Page 13: ......
Page 15: ......
Page 16: ...1 PerformanceVerification...
Page 28: ...2 Calibration...
Page 56: ...3 RoutineMaintenance...
Page 59: ...3 4 Routine Maintenance Model 2500 Service Manual...
Page 60: ...4 Troubleshooting...
Page 74: ...5 Disassembly...
Page 81: ...5 8 Disassembly Model 2500 Service Manual...
Page 82: ...6 ReplaceableParts...
Page 93: ...6 12 Replaceable Parts Model 2500 Service Manual...
Page 94: ...A Specifications...
Page 98: ...B CalibrationReference...
Page 108: ...C CalibrationProgram...
Page 117: ......
Page 119: ......
Page 120: ......
Page 121: ...Keithley Instruments Inc 28775 Aurora Road Cleveland Ohio 44139 Printed in the U S A...