Illumination And Buzzer - Ericsson PF 768 Troubleshooting Instructions

PF768, Standard Electrical Repairs

8 Illumination and buzzer.

8.1 Type of fault.
Insert a dummy battery and a SIM card into the phone, press the On/Off key and
wait for the phone to get serv (towards the net or a GSM test instrument).
• If the phone doesn't beep at start, go to "menu/ring level" and try to increase the
• If one or more of the LEDs at the display illumination isn't lit at start, proceed to
• If one or more of the LEDs at the keyboard illumination isn't lit at start, proceed
• If the top indicator doesn't blink green when the phone has got serv, proceed to
• If the top indicator blinks green when the phone has got serv, lower the battery
8.2 Buzzer faint or dead.
Open the phone and check for liquid damages.
The front side of the circuit board is shown in fig. 8.1.
ring level to full (not from full to step since that won't generate any sound). If the
sound is faint or if you can't hear it at all, proceed to section 8.2
section 8.3.
to section 8.3.
section 8.4.
voltage to 4.2V. The top indicator should then start to blink red, the battery indi-
cator should show an empty battery and the phone should warn with a beep.
* If the battery indicator doesn't show an empty battery, the top indicator
doesn't blink red and the phone doesn't warn with a beep the phone needs a
voltage calibration.
* If the top indicator doesn't blink red but the other things work, proceed to
section 8.6.
* If both the top indicators colours are faintly glowing and the buzzer sounds
faintly, proceed to section 8.7.
4/00021-2/FEA 209 544/11.C
Fig. 8.1
42
(68)