Common Problems; No Communication During Flash; No Communication During Alignment; Failed Self Test/Calibrate - Nokia 2255 Baseband Description And Troubleshooting

Nokia Customer Care

Common Problems

The following section has a list of common problems, along with some standard checks.

No Communication During Flash

• Make sure there is a good connection between flash adaptor and the mobile
terminal
• The mobile terminal has to be powered by prommer (FPS-8)
• Check the Baseband regulators VR3, VIO, VCORE, VFLASH1
• The mobile terminal will not able to flash without 19.2Mhz clock into UPP
• Check that 32Khz Clock is present
• Check BSI, MBUS, FBUSRx, FBUSTx, PURX, SLEEPX for bad solder joints between
UEMC and UPP
• Check the Flash bus signal and VPP voltage level

No Communication During Alignment

• Check all connections between test fixture, cables and the mobile terminal
• Make sure the mobile terminal is in Local Mode. If not, check BSI signal level
• Make sure the mobile terminal is programmed/flashed

Failed Self Test/Calibrate

• Make sure the mobile terminal is in local mode
• Make sure power supply provides enough current (usually approximately 500mA
and 2A for tuning)
• Use the troubleshooting guide's flow chart to verify the failed circuit
• Check the signals and voltage levels as described in the troubleshooting guide

Mobile Terminal Not Powering Up

Refers to when no power causes the mobile terminal to not able to flash, not to get into
local mode and similar problems.
• Check the baseband regulators – VR3, VIO, VFLASH1, VCORE dc/dc, PURX
• Check VCTCXO 19.2MHz signal at UPP input
• Check that 32Khz Clock is present
• Check power-up sequence
• Check the Flash IC, flash bus signals, and voltage level

Shut Down After 32 Seconds

• Check for the absence of 32KHz SleepCLK
ISSUE 1 10/2005
©2005 Nokia Corporation
Baseband Description and Troubleshooting
Company Confidential
2255 (RM-97)
Page 33