NSW-5
Disassembly and Troubleshooting Instructions
PAMS Technical Documentation
Page 43
Issue 1 10/00
Nokia Mobile Phones Ltd.
Power Control Loop
Power control section is basically similar for both bands, except for that
both bands have their own directional coupler and detector. The power
control is actually made in EROTUS IC.
Is DETO vs. output
power and TXC
OK?
See chart below.
Check power
control components
near N750
Press N750
Change N750
Change N700
Is TXLX functionality
OK ?
TXLX are LOW on
power levels PL 2…7
Check PIN diode
bias components.
Check BB controls.
(BaseBand)
Is V929, V930
voltage drop about
0.3–0.4 V
Check V930, V929
Check bias circuit
around diodes.
Y
N
N
Y
N
Note !
See DETO vs. Output power
curve
Note:
1. DETO and TXC will be
about same in each mode.
2. TXA is high during modulation.
3. TXLX signals will draw about
4mA current in high state.
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