Front Panel Section; Figure 3-1 Diagram Of Front Panel - Hytera MD78X Service Manual

Service Manual

Front Panel Section

3. Front Panel Section
The front panel contains the speaker, keys, power switch, volume control knob, LCD display and other
parts. The block diagram is shown as the figure below.

Figure 3-1 Diagram of Front Panel

Power Supply
The main board supplies power to the front panel via U902, so that the LED, backlight and USB
devices can be powered up. Then the power is further fed to U5, so as to supply LCD and U1
(serial-to-parallel converter IC).
Keys
The front panel has ten keys whose functions vary with different operation modes, as described in the
table below. The operation of each key is identified by a 3X4 matrix keyboard.
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