User Guide

NSD-5
10. Troubleshooting PAMS Technical Documentation
Page 14 Nokia Corporation Issue 1 05/02
Check that the 32kHz clock turns on when attempting to power up.
Check the power circuitry. This includes Vbat, Vref, and all of the linear regulators.
Power Doesn’t Stay on or Phone is Jammed
If this type of fault occurs after flash programming, there are most likely open joints in
ICs. Solder the IC joints. Normally, the power will be switched off by CCONT(N302) after
30 seconds if the CCONT watchdog cannot be served by software. This updating can be
seen with an oscilloscope at CCONTCSX(TPD334). In normal cases, there is a short pulse
from “1” to “0” every 8 seconds.
Because of underfill, check the supply voltages, clock signals, and power sequence. If the
power sequence fails, there are some open connections under MAD4 or compomemory. If
everything appears to be correct, it is best to erase the flash memory and try to reput the
software to the phone again.
Flash Programming Fails
The flash programming can be done via flash connector X052 or via dedicated PCB pads
(J56,J57). In production, the first programming is done via flash connector. After this, the
flash connector is cut away; as a result, the programming must be done via PCB pads vis-
ible through the shield under the battery. The fault-finding diagrams for flash program-
ming are shown in the start-up sequence diagram.
In the case of flash programming errors, the flash prommer may provide some informa-
tion about a fault. The fault information messages could be:
- MCU doesn’t boot
- Serial clock line failure
- Serial data line failure
- External RAM fault
- Algorithm file or alias ID not found
- MCU flash Vpp error
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 ohmeter) determined whether
there is a possible short between two or more of the address or data lines.
Audio failures
If audio fails to be heard from the earpiece (or XEAR), check the following:
Check earpiece contacts.