
UHF1(400-470MHz)
Troubleshooting Flow Chart
24
6. Troubleshooting Flow Chart
6.1
Control Circuit
Check the control
circuit
The product
powers on
normally?[1]
Check
U304 , U306 , U303
and control circuit
Led works normally?
3V3D is
normal?
Replace LED
Check
U2013 , U309
Reset
Check the power-
on circuit and
U2014
Check U305
Yes
No
Yes
No
Yes
Yes
No
No
Yes
No
No
19.2MHz crystal
oscillator is normal?[3]
1V3D
is normal?
1V8D
?
The control circuit
is normal.
The RF circuit is
normal?[2]
Yes
No
Complete
Yes
is normal?
Description of Normal Situations:
[1] After the radio powers on, the LED indicator and alert tone works properly.
Summary of Contents for PD502
Page 1: ...PORTABLE...
Page 5: ...VHF 136 174 MHz...
Page 13: ...VHF 136 174 MHz Exploded View and Packaging Guide 7 3 2 Packaging Guide...
Page 18: ...VHF 136 174 MHz Circuit Description 12...
Page 43: ...PCB 3 9 PCB VHF 136 174 MHz...
Page 44: ...PCB 3 VHF 136 174 MHz...
Page 71: ...UHF1 400 470 MHz...
Page 79: ...UHF1 400 470MHz Exploded View and Packaging Guide 7 3 2 Packaging Guide...
Page 84: ...UHF1 400 470MHz Circuit Description 12...
Page 108: ...UHF1 400 470MHz PCB 36 9 PCB...
Page 109: ...UHF1 400 470MHz PCB 37...
Page 136: ...1616300000260 2014 03 17 L07157 4...