Service manual

Testing the
Multiplexer
You can use the tests and checks in Chapter 2, "Verification Tests," and the
information in Table 4-4 to isolate the problem to a relay, to a component,
or both. For example, if Test 2-1: Closed Channel Resistance Test failed
for channel 0, replace relay K100, etc. See Chapter 3, "Replaceable Parts,"
or Appendix B, "Backdating Information," for replaceable parts lists and
locator diagrams, depending on the serial number of your multiplexer.
Table 4-4. Checks for Relay/Component Failures*
If Test 2-1 failed
for this Channel:
Check/Replace these
Relays/ICs:
Channel 00
Channel 01
Channel 02
Channel 03
Channel 04
Channel 05
Channel 06
Channel 07
Channel 08
Channel 09
Channel 10
Channel 11
Channel 12
Channel 13
Channel 14
Channel 15
Channels 00 - 07
Channels 08 - 15
Channel 90
Channel 91
Channel 92
Channels 90 - 92
Channels 00 - 15 and
90 - 92
K100
K101
K102
K103
K104
K105
K106
K107
K108
K109
K110
K111
K112
K113
K114
K115
U1, U21, U38
U2, U21, U30
K90
K91
K92
U3, U21, U25
CR2, Q1, U3, U6, U8,
U12, U15, U20, U21,
U22
If these items
failed:
Replace:
Channel 93
Device Type ID
CRESET failed
K93
U10
U9, U21
* See Test 2-1: Closed Channel Resistance Test for information.
58 Service Chapter 4