Hytera MD652, Service Manual

Page: 137 / 207

VHF1 (136
‐
174 MHz)
Troubleshooting Flow Chart
29
6. Troubleshooting Flow Chart
6.1
Control Circuit
Control circuit check
Power-on display is
normal?
Palm microphone is
connected normally?
Crystal X8001
19.2 MHz is normal?
U2007(5VD) is normal?
U2001(3V3D) and
U2002(3V3_GPS) are
normal?
U2004(1V8D) is normal?
RF circuit cannot be
driven normally
Check
U2009 and U2008
Reconnect the palm
microphone
U2009(5VA_FGU) and
U2008(3V3A_FGU) are
normal?
Replace crystal
X8001
Check power-on circuit
and peripheral circuits of
U2007
Check power-on circuit
and peripheral circuits of
U2004
Check power-on circuit
and peripheral circuits of
U2001 and U2002
Check power-on circuit
and peripheral circuits of
U2010
Control circuit is normal
U2010(1V6D) is normal?
Confirm control circuit
Control head cable is
normal?
Replace the cable
Yes
No
No
No
No
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes