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PAMS Technical Documentation
Flash Align
Test 9
High current: This indicates that the problem is likely caused by a shorted
component. Check orientation of major components (including RF), and
check for shorts. Likely components are those which are powered directly
from Vbat such as CCONT, the PAs, and various capacitors.
Low current: This indicates that CCONT is not powering on. Verify
CCONT circuitry.
Test 10
Flash: Failure to flash is the main baseband failure. Check all the CCONT
regulators, especially Vbb, VR1, and VR6 for shorts. Check clocks and
reset circuitry. Check for shorts on the address, data, and chip enable
lines on the memories and MAD4. If a short is detected, it may be that it is
beneath the BGA flash and may have to be replaced.
NOTE: Unfortunately, there is no ROM software that can be run when the
phone does not flash. Typically, this software would be used to test all of
the interfaces between MAD4 and its peripherals. Therefore, it must be
visually (or by Ohmmeter) determined whether there is a possible short
between two or more of the address or data lines.
In the field
Solder joints may be adequate for passing manufacturing requirements,
however, they may not hold up to mechanical stress or heat cycling.
Cracked or broken solder may cause failures to occur from simple use.
Reflowing some of the major components may fix problems where the
phone exhibits strange behavior (some buttons may not work, the phone
may not ring, etc.) or may not power on anymore.
Battery will not charge
If the battery won't charge (phone won't allow the battery to charge),
check CHAPS and the charging circuit. It may also be necessary to verify
the A/D functionality of CCONT since this is the method of detecting bat-
tery type, charger type, etc
Audio failures
If audio fails to be heard from the earpiece (or XEAR), it could be a num-
ber of possible problems. Check the following:
Check earpiece contacts.
Verify that the CAFÉ EARP and EARN bias is on. If necessary, check the
entire receive path—Rx voice data comes from the RF through the RXIQ
bus (CDMA) or LIM_P and LIM_N (AMPS), then to MAD4 through RXD
(11:0) (Refer to schematic). See the Baseband section of the Service
Manual for more detail on RXD bus usage.
The Rx voice data then goes back to CAFE on CAFESIO (0), and then to
the earpiece or XEAR. CAFESIO (2) must also be active.
Issue 2 09/00
Disassembly / Troubleshooting Instructions
E Nokia Mobile Phones Ltd.
NSD–1
Page 11
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Table of Contents
Troubleshooting
