Sangean ATS-909X - WORLD BAND RADIOS, Service Manual

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TROUBLESHOOTING FLOW CHART
(1) The radio power can not turn to ON
NO
Check whether clock time show on the
LCD and the color is flashing.
Check the power supply of µ -com and
connectors. (CN302, W302)
YES NORMAL
Check X301, X302.
NO
Check whether battery mark is flashing on
the LCD?
Check whether any key had short.
YES
NO
Check the power detect circuit Q308,
D308 and IC306.
Check circuit of µ -com IC305.
(2) PLL do not work in AM band
NO
Check whether TP9 the voltage is more
than 14Vdc. While the radio set to SW
band.
Check the dc/dc counter circuit Q43, Q44
and T12.
YES
NO
Check TP10 tuning voltage>5 and <12
while receiving frequency is 29.9MHz.
<3V or >14V
Check AM 1’st local oscillator Q32, Q34,
Q35, T11 and D34.
YES
Check AM receiving loop; PLL is normal.
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