Hytera PD78XG - Page 219

Service Manual UHF2 (450-520MHz) Information
209
FGU
FGU check
Check the power
supply circuit.
5VFGU, 3V3ARF,
3V3DRF are normal?
VCO oscillates?
Q106 、Q110
输出是否正常？
反馈是
否正常？
Yes
Yes
Yes
CV voltage is normal?[3]
Feedback is output?
Yes
Yes
Yes
No
Replace Q106
and Q107.
Q106 and Q107
are normal?[1]
Q104 and Q108
are normal?[2]
No
No
Yes
Replace Q104
and Q108.
No
Check Q104, Q108 and
peripheral components.
Yes
No
L110 and L116 are
normal?[4]
Replace L110 and
L116.
No
Q101 and Q102
are normal?[5]
Check the
feedback circuit.
No
19.2MHz crystal
oscillates?
Check the
19.2MHz circuit.
No
Sky72310 clock is
normal?[6]
Completed
Yes
Check the data
circuit of the
control circuit.
No
Check Q101, Q102 and
peripheral components.
Replace Q101
and Q102.
No
Yes