Keithley 2182, Service Manual, Page: 8 / 120

4 Troubleshooting
Introduction ................................................................................ 4-2
Repair considerations ................................................................. 4-2
Power-on self-test ....................................................................... 4-3
Front panel tests .................................................................. 4-3
KEY test .............................................................................. 4-3
DISP test .............................................................................. 4-3
Principles of operation ................................................................ 4-4
Power supply ....................................................................... 4-4
Display board ...................................................................... 4-5
Digital circuitry ................................................................... 4-6
Analog circuitry ................................................................... 4-7
Troubleshooting ........................................................................ 4-10
Display board checks ........................................................ 4-10
Power supply checks ......................................................... 4-11
Digital circuit checks ......................................................... 4-12
Analog circuit checks ........................................................ 4-13
Analog signal switching states .......................................... 4-14
No comm link error ........................................................... 4-16
5 Disassembly
Introduction ................................................................................ 5-2
Handling and cleaning ................................................................ 5-2
Handling PC boards ............................................................ 5-2
Solder repairs ....................................................................... 5-2
Static sensitive devices ........................................................ 5-3
Assembly drawings .................................................................... 5-3
Disassembly ................................................................................ 5-4
Case cover removal ............................................................. 5-4
Motherboard removal .......................................................... 5-5
Front panel disassembly ...................................................... 5-5
Main CPU firmware replacement ............................................... 5-6
Changing trigger link lines ......................................................... 5-7
Removing power components .................................................... 5-8
Power transformer removal ................................................. 5-8
Power module removal ........................................................ 5-8
Instrument reassembly ................................................................ 5-9
Power module connections .................................................. 5-9
Board installation ................................................................ 5-9