7.1 Uplink Problem - Nokia Mobile Phones NSE-5 Series Service Manual

NSE–5
Troubleshooting

7.1 Uplink Problem

Uplink is broken
Voltage at E101 is 1.8V
Voltage at E100 is 0.3V
during call
Yes
Voltage on COBBA side of
C117 & C121 is 1.4V during call
Yes
Audio voltage (few
millivolts) on COBBA side of
C117 & C121 during call
Yes
Check N200
Page 18
No
Check:
microphone connections (through slide)
micbias components (V111, R148, R116,
R119, V100)
Micbias control line (one side of R149)
during call
No
Check N200 COBBA
No
Check C117, C121,
Slide and PCB
Figure 15.
PAMS
Technical Documentation
Issue 1 07/99