Hytera MD78X Service Manual page 550

Service Manual VHF (136-174MHz 25W) Information
Description of Normal Situations:
[1] Detect the oscillation frequency of RX TP123 and TX TP111 using a spectrum analyzer or the
communication test set.
[2] Check whether switches (Q108, Q112, Q101 and Q105) are turned on and output 4.3V
[3] Check whether the emitter-base voltage of the four transistors (Q106, Q110, Q100 and Q103) is
about 0.7V under normal RX/TX status.
[4] Check the CV of TP124. The normal value should range from 0.5V to 4.5V.
[5] Check whether U100 is supplied by 5V and 3.3V normally.
[6] Check whether the power from TP109 to PLL is about -13dBm.
[7] Check whether TP100 outputs 19.2MHz signal.
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