User Guide

RH-10
System Module CCS Technical Documentation
Page 24 Nokia Corporation Confidential Issue 1 09/2002
Interface
The F100 fuse protects the phone from too high currents (e.g., when broken or pirate
chargers are used). L100 protects the engine from RF noises, which may occur in the
charging cable. V100 protects the UEM ASIC from reverse polarity charging voltage and
from too high charging voltage. C105 is also used for ESD and EMC protection. Spark
gaps are used for ESD protection right after the charger plug.
Test Interfaces
Production Test Pattern
Interface for RH-10 production testing is a 5-pin pad layout in BB area (see figure
below). Production tester connects to these pads by using spring connectors. Interface
includes MBUS, USRX, FBUSTX, VPP, and GND signals. Pad size is 1.7mm. The same pads
also are used for AS test equipment such as module jig and service cable.
Other Test Points
BB ASICs and flash memory are CSP components and the visibility to BB signals is very
poor. This makes measuring of most of the BB signals impossible. In order to debug BB at
least at some level, the most important signals can be accessed from 0.6mm test points.
The figure below shows test points located between UEM and UPP. There is an opening in
the baseband shield to provide access to these pads.