User Guide

TROUBLESHOOTING
9526ARo
6–2–7
NHC–4
Technical Documentation
Copyright  Nokia Mobile Phones
Troubleshooting Diagram; Flash Programming OK, part 1
YES
FLASH programming OK
MBUS
registration
OK?
Display:
selftest failed
D302/MCU/pin 3
D401/ASIC/pin 56
rstrobex
Power
stays on?
YES
YES
NO
Display:
selftest failed
NO
Short circuits in data
data lines. data line
disconnected, VREF
unconnected
MBUS line X1/5
+5 V after pwr on?
R316
+ 5 V?
VBATT
pins 5, 20?
Check X1
N100/XRESET/pin 8
+5 V after pwr on?
C106 OK ?
R100 OK ?
Change N100
MCU/D302/pin67/RDX
+5 V after pwr on (J109)?
NO
If D302 at
pin 66/TXD
doesn’t apply
+5 V change
D302
D401 pulses
pin 91
Change
ASIC
D401
Change first
D302
If R317 is OK
change D302
NO
NO
NO
Power supp. to the logic
circuits +5 V after pwr on?
Change N100
NO
NO
YES
YES
YES
NO
YES
YES
YES
NO
YES
YES
2
3
YES
ASIC OK