Hytera PD362, Service Manual

Page: 104 / 141

Uc (430
‐
470 MHz)
Troubleshooting Flow Chart
29
6.4
FGU Circuit
Q 106
、
Q 110
输出是否正常？
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
Yes
No
Yes
No
No
No
No
Completed
Yes
No
No
Yes
FGU check
Check the power supply
circuit.
3VFGU, VCC_CP and
3VOA_FGU_PLL are
normal?
VCO oscillates?
CV is normal?[3]
Q8007 and Q8010 are
normal?[5]
Replace Q8007
and Q8010.
Q8002, Q8003, Q8005,
Q8009 and Q8011 are
normal?[1]
Replace Q8002,
Q8003, Q8005, Q8009
and Q8011
Q8004/Q8008 are
normal?[2]
Check Q8004, Q8008
and peripheral
components.
Replace Q8004 and
Q8008.
Replace L8018 and
L8045.
L8018 and L8045
are normal?[4]
Feedback is output?
Check the feedback
circuit.
19.2MHz crystal
oscillates?
Check the 19.2MHz
circuit.
Sky72310 clock is
normal?[6]
Check the data control
circuit of Sky72310.
Check Q8007,
Q8010 and
peripheral
components.
No
Signal
Amplitude is
normal?[7][8]
Check the data control
circuit of Sky72310.
Description of Normal Situations:
[1] During transmission , Q8002 Pin 3 outputs the voltage of about 3 V. During receipt , Q8003 Pin 3
outputs the voltage of about 3 V.
[2] During transmission , the voltage is about 1.13 V at pole E of Q8008, about 2.84 V at pole C and about