Alert Problems - Ericsson T28S Troubleshooting Manual

9 Alert Problems

9.1 Type of fault
Insert a dummy battery and a SIM-card into the phone and start it up by pressing the On/Off
key. Wait for the phone to get SERV (towards the test instrument or the net).
If the phone does not beep at start-up, use the menu to increase the ring volume (not from full
to "step", as that does not generate any sound).
If the sound is faint or there is no sound at all, go to section 9.2.
Use the menu to set the vibrator to ON mode. If the phone does not vibrate when the settings
are stored, go to section 9.4.
9.2 Buzzer faint or dead
Open the phone and check for liquid damage.
Make sure the buzzer (H600) is not incorrectly soldered.
If the solder joints are correct, replace H600.
Assemble the phone and try again as described in section 9.1.
Open the phone, power up the board and start it by pressing the On/Off key.
Measure the voltage at pin 3 of H600 (3.70 ± 0.05 V).
If the voltage is incorrect, replace R603.
If that does not help there is a foil damage, send the unit on according to the local company
directives.
Measure the resistance of R651 (1 kohm).
If the resistance is incorrect, replace R651.
If the resistance is correct, replace V606.
If that does not help, replace V605.
If the fault remains, send the unit on according to the local company directives.
4/00021-2/FEA 209 544/19 E
Trouble Shooting Guide, Standard
25(29)