Disabling illumination when running from external d.c.

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The AR8200 (series 1 and 2) has a back light which can be switched on in various ways from the lamp config menu (page 106 – hand book). This, however only takes effect when the set is used from internal batteries. If external power is used, the back light is permanently on. A small modification is possible to allow front panel lamp switching when using external power. To do this, simply disconnect the unswitched supply line from the power socket to the lamp switching IC. In practice this is easily done by removing R512 (100kohm) from the control PCB (the one with the LCD, micro etc ). The set has to be stripped down to the control board (take care with the ribbon cables). The front (LCD) side of the board has to be exposed. The only soldering required is to remove the speaker connections and then to remove the resistor itself.

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