Nokia NSE–6 Series Disassembly & Troubleshooting Instructions page 8

NSE–6
Disassembly & Troubleshooting Instructions
In cases of unsuccesful flash programming there is a possibility to check
short circuits between the memories and the MCU (MAD2). It is useful to
do this test, when the fault information is: MCU doesn't boot, Serial clock
line failure or Serial data line failure. The test procedure is following:
1. Connect testpoint J229 to ground.
2. Switch the power on.
3. If the voltage level in testpoint J225 is 2.8 V ("1"), the interface is OK. If
there is a short circuit, the voltage level in testpoint J225 stays low and 32kHz
square wave signal can be seen in the lines which are already tested.
It must be remembered that this test can only find short circuits, not open
pins. In addition upper data lines (15:8) of flash memory D220 are not in-
cluded in this test.
Page 8
CCONT pin 54
MAD pin 38
MAD pin 134
selftest
passed
Technical Documentation
( PURX )
( MCUAD0)
( ExtSysResX))
J225
PAMS
Original 08/98