Power Control Loop - Nokia NSW-5 Series Service Manual

PAMS Technical Documentation

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 V929, V930
voltage drop about
0.3–0.4 V
Y
Is TXLX functionality
OK ?
TXLX are LOW on
power levels PL 2 7
Y
Is DETO vs. output
power and TXC
OK?
See chart below.
Issue 1 10/00
Disassembly and Troubleshooting Instructions
Check V930, V929
N
Check bias circuit
around diodes.
N Check PIN diode
bias components.
Check BB controls.
(BaseBand)
Check power
N
control components
near N750
Press N750
Change N750
Change N700
E Nokia Mobile Phones Ltd.
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.
NSW-5
Page 43