Key Problems - Ericsson A2618s Troubleshooting Manual

8 Key Problems

Start up the unit by pressing the On/Off key.
If the unit does not start at all, go to chapter 3 ("On/Off Problems").
If the unit starts but none of the keys are functional, go to section 8.1.
Use the Service Test menu and choose "Keyboard".
Every time a key is pressed a text-feedback is displayed, showing the information of which
key that was pressed.
All keys including the side key (Volume button) can be tested.
Pressing the "Yes" or "No" key will end the test and return to the Service Menu.
If one or more of the keys are out of order, go to section 8.1.
If only the side key is faulty, go to section 8.2.
8.1 One or more of the keys are out of order
Open the unit and check for liquid damage.
No action should be taken for liquid damaged units, send the unit on according to the local
company directives.
Remove the flex-film, clean the pads and mount a new flex-film.
Test the keys again, using the Service Test menu.
If the fault still remains, send the unit on according to the local company directives.
8.2 Side key out of order
Open the unit and check for liquid damage.
No action should be taken for liquid damaged units, send the unit on according to the local
company directives.
Check that there is 2.75V ± 0.10 V
If the voltage is incorrect, measure the resistance of R853 (33 ohms) and R857 (33 ohms).
If the resistance is incorrect, replace the faulty component.
Replace the side-key switch.
Test the keys again, using the Service Test menu.
If the fault still remains, send the unit on according to the local company directives.
4/00021-2/FEA 209 544/25 A
at X851 and X852.
DC
Trouble Shooting Guide, Standard
20(24)