Ericsson T28S Troubleshooting Manual page 24

8.3 Volume key out of order
Replace J820.
If the fault remains, send the unit on according to the local company directives.
8.4 Flip function out of order
The flip does not stay in closed position, replace the front and flip.
The active flip function is out of order.
Open the phone and check for liquid damage.
Measure the voltage at pin 1 of N600 (2.70 – 2.85 V).
If the voltage is incorrect, send the unit on according to the local company directives.
If the voltage at pin 1 of N600 is correct, measure the voltage at pin 2 of V630 (3.70
± 0.05V).
If the voltage at pin 2 of V630 is incorrect there is a foil damage, send the unit on according
to the local company directives.
If the voltage at pin 2 of V630 is correct, replace V630 and V631.
If that does not help, replace N600.
Measure the resistance over R685 (100 kohms), if incorrect replace it.
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
24(29)