Nokia 7110 - Microphone Doesnt Work

CONFIDENTIAL 25 (30)
NSE-5
Service & Analysis Center Europe Repairhints Version 1.0 Approved
SACE AMS Training Group 30.07.2000
Repairhints_nse5_002508 Checked by:
AMS TRAINING GROUP
Approved by:
SACE
MICROPHONE DOES NOT WORK
-Also see SB 018 –
Note : First of all check the mechanical condition of the phone and slide for mechanical
damage or stuck. (PogoPins).
Probable reasons:
- Shorts between contact tracks and slideflex.
These shorts often occur at the end of the slide-cover (friction-dust).
If this happens, clean the flex with dustfree cloth, especially in the bottom corner.
- The Pogo pins in microphone housing get stuck. If this happens, change
A-Cover.
- Check the internal contact springs from Pogo-pins and their connector pads
on the PCB.
- Check impedance (~ 1,8k) , change slide cover if necessary.
- Check solderings of Z103/104, C106/107/132.
- Check signals (given over MPA-1 =audio test probe ) at V100 in & out.
- Check V_COBBA at V111 (2,8VDC).
- Check voltage ( during call ) at C117/121 ( 1,4VDC ) , at E100 ( 0,3V ), E101 ( 1,8V ).
- Change COBBA if all of the above works.
Rewriting of IMEI and SIMlock data is necessary after changing the COBBA!
- If the error persists, MAD or PCB should be the reason.