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UHF5 (806MHz
–
941MHz)
Troubleshooting Flow Chart
29
6. Troubleshooting Flow Chart
6.1
Control Circuit
Power-on indication is
normal?[1]
Cannot drive
the RF circuit
properly
Verify the
control circuit
Front panel FFC is
normal?[2]
X302 (19.2 MHz) is
normal?
[3]
U902 (5VD)
is normal?[5]
U900(3V3D) and
U901(3V3D) are
normal?[6]
Replace FFC
Check
U905 and U909
Replace X302
Check power-on
circuit and peripheral
circuits of U902
Check power-on circuit
and peripheral circuits
of U900 and U901
Yes
No
Yes
No
Yes
Yes
No
No
Yes
Yes
No
No
U903 (1V8D) is
normal?[7]
U919 (1V6D) is
normal?[8]
Check power-on circuit
and peripheral circuits
of U903
Check power-on circuit
and peripheral circuits of
U919
No
Yes
Yes
No
U905 (5VA) and
U909 (3V3A) are
normal?[4]
Check the
control circuit
End
Description of normal situations:
[1] The screen is not blurred upon power-on.
[2] The FFC connects correctly.
[3] The frequency of signal from X302 is 19.2 MHz.
Содержание MD78X
Страница 1: ...DIGITAL MOBILE RADIO SERVICE MANUAL...
Страница 5: ...UHF1 400 470 MHz...
Страница 14: ...UHF1 400 470 MHz Exploded View and Packing Guide 7 3 2 Packing Guide...
Страница 56: ...UHF1 400 470 MHz Interface Definition 49 Pin No Name Description 39 GND Grounding 40 PWB_IN Power On Off signal...
Страница 62: ...55 9 PCB View MD78X MD78XG PCB View Front Panel Top Layer...
Страница 63: ...56 MD78X MD78XG PCB View Front Panel Bottom Layer...
Страница 64: ...MD78X MD78XG PCB View Main Board Top Layer 57...
Страница 65: ...MD78X MD78XG PCB View Main Board Bottom Layer 58...
Страница 111: ...UHF2 450 520 MHz...
Страница 120: ...UHF2 450 520 MHz Exploded View and Packing Guide 7 3 2 Packing Guide...
Страница 167: ...54 9 PCB View MD78X MD78XG PCB View Front Panel Top Layer...
Страница 168: ...55 MD78X MD78XG PCB View Front Panel Bottom Layer...
Страница 169: ...MD78X MD78XG PCB View Main Board Top Layer 56...
Страница 170: ...MD78X MD78XG PCB View Main Board Bottom Layer 57...
Страница 216: ...UHF3 350 400 MHz...
Страница 225: ...UHF3 350 400 MHz Exploded View and Packing Guide 7 3 2 Packing Guide...
Страница 272: ...54 9 PCB View MD78X MD78XG PCB View Front Panel Top Layer...
Страница 273: ...55 MD78X MD78XG PCB View Front Panel Bottom Layer...
Страница 274: ...MD78X MD78XG PCB View Main Board Top Layer 56...
Страница 275: ...MD78X MD78XG PCB View Main Board Bottom Layer 57...
Страница 321: ...UHF5 806 941 MHz...
Страница 330: ...UHF5 806MHz 941MHz Exploded View and Packing Guide 7 3 2 Packing Guide...
Страница 376: ...53 9 PCB View MD78X MD78XG PCB View Front Panel Top Layer...
Страница 377: ...54 MD78X MD78XG PCB View Front Panel Bottom Layer...
Страница 378: ...55 MD78X MD78XG PCB View Main Board Top Layer...
Страница 379: ...56 MD78X MD78XG PCB View Main Board Bottom Layer...
Страница 414: ...VHF 136 174 MHz...
Страница 423: ...VHF 136MHz 174MHz Exploded View and Packing Guide 7 3 2 Packing Guide...
Страница 468: ...PCB 52 9 PCB View MD78X MD78XG PCB View Front Panel Top Layer...
Страница 469: ...PCB 53 MD78X MD78XG PCB View Front Panel Bottom Layer...
Страница 470: ...MD78X MD78XG PCB View Main Board Top Layer 54...
Страница 471: ...PCB 55 MD78X MD78XG PCB View Main Board Bottom Layer...