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TM
115820-890-20-3
TROUBLESHOOTING GUIDES. Continued
3.2.
TS Guide 21. NO SIDETONE HEARD AT LS-671
ACTIONS
CHECKS
STEPS
NO:
Go to 21.2
CX-13417
21.1 Define problem
YES: Go to 21,6
present at MB?
N/A
N/A
21.2 Set LS-671 CB1 to OFF
Remove VAA from MB
N/A
N/A
Measure resistance at VAA:
YES: Go to 21.3
NO:
Replace VAA
(RT-A) J3 Pin D to P1 Pin M
more than 20K
(RT-B) J4 Pin D to P1 Pin U
or less than
28K Ohms?
N/A
N/A
21.3 Remove CX-13292 from MB J3/J4
Check continuity at MB J5, Pin U
Open?
NO:
Go to 21.4
to J3/J4, Pin U
YES: Replace MB
21.4 Remove CX-13292 from LS-671 J1
N/A
N/A
Check continuity at MB:
Open?
NO:
Go to 21.5
(RT-A) J3 Pin D to P1 Pin M
YES: Replace CX-13292
(RT-B) J4 Pin D to P1 Pin U
YES: Replace CX-13292
21.5 Check continuity at CX-13292
Open?
P1, Pin S to P2, Pin A*
Replace LS-671
NO:
N/A
21.6 Set LS-671 CB1 to OFF
N/A
Remove CX-13417 from MB J3/J4
N/A
N/A
Remove CX-13292 from CX-13417
N/A
N/A
Connect CX-13292 to MB J3/J4
N/A
Set LS-671 CB1 to ON
N/A
N/A
Press PTT; count into HS
Sidetone
YES: Replace CX-13417
NO:
heard?
Go to 21.2
*
P1 is speaker end; P2 is radio end.
TS Guide 22. RADIO WILL NOT OPERATE WITH DATA DEVICES
STEPS
CHECKS
ACTIONS
22.1 Run self-test on RT
Self-test
NO:
Go to 22.2
failed?
YES: Replace RT
22.2 Run self-test on data device
Self-test
NO:
Go to 22.3
failed?
YES: Replace data device
22.3 Test interface cable
Open or
NO:
Go to 22.4
shorted?
YES: Replace cable
22.4 Replace data device with known
N/A
N/A
good data device*
Operate system
System
NO:
Replace RT
operates?
YES: Replaced data device