(800/900Mhz, Open Architecture, No Transmit Deviation) - Motorola Handie-Talkie MTX Series Theory/Troubleshooting Manual

INT
Check Continuity
NO
VDC
between V Gnd
at MK401
& MK401 = 2k
and Gnd
YES
Acoustic Couple
1k Tone to Int. Mic.
YES
Check
Audio
B8-U701
NO
Check Components
C713, C793, R207
TROUBLESHOOTING FLOW CHART #7B

(800/900MHz, Open Architecture, No Transmit Deviation)

No TX Dev. Ext.
Setup - Inject 80mV-1k
Signal into Ext. Mic. Path
Check
NO
Audio
14-J701
YES
Check
NO
Audio
A7-U701
YES
Check
NO
Audio
U701-H8
YES
Check
NO
Audio
Pin 3 J301
YES
Check
NO
Audio
Pin 5 U204
YES
Check
NO
Audio
Pin 30 U204
YES
Check Components
C247, C246, R213,
C275, R211
Check Continuity
between Pin 14-J701
& Pin 3 J403
Check Components
R703, R704, C712
HEARCLEAR ONLY
Change U701
Replace Jumper Flex
Check Continuity
Between
Pin 3 J301 &
Pin 5 U204
Change U204
Check
NO
Change U701
Audio
A6 - U701
YES
Check
NO
Audio
Check Components
D3 - U601 C614, C723, & C615
YES
Check
NO
Audio
Change U601
F3 - U601
YES
Check
NO
Audio Check C616
C7 - U701
MA
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