Hytera PD362, Service Manual

Page: 29 / 141

Troubleshooting Flow Chart
Ua (400
‐
440 MHz)
22
6. Troubleshooting Flow Chart
6.1
Control Circuit
6.1.1
No ' isplay upon 3 ower-on or $ bnormal ' isplay
No
Yes
Yes
Yes
Yes
Yes
No
Completed
Yes
No
The voltage of TP304
(V_BAT) is normal? >@
Check whether the battery voltage
is too low or whether the contact
spring plate works well
No display upon power-on or
abnormal display >@
The POWER_KEY- signal
(R306) is at high level
when holding down the
Power On/Off key?
Check whether the keypad
board and its connection are
normal
The power supply of LCD
is normal?
No
Check U307
The LCD clock, reset and
data signals are normal?
Check whether the LCD and
its connection are normal
No
MCU power supply and clock
are normal?
No
Check whether X100 crystal
oscillator and U302 are
normal
MCU reset signal (14-pin) is
normal?
Check U103
1V2D, 3V0D, 3VRT and
3VFGU are normal?
No
Check U300, U302, U306 and
U304
Yes
12.288MHz clock is
normal?
No
Check the clock generation
amplifier circuits of X200, Q200
and U204
Yes
Description of Normal Situations:
[1] The LED indicator works properly after the radio SRZHUVRQ .
[2] The radio can be powered on normally when the battery voltage is higher than 3.15 V.