Trouble Shooting Guide, Advanced
4/00021-3/FEA 209 544/25 C
Ericsson Mobile Communications AB
76(78)
24.2 Chip revision (CPU, SDSP and AASIC)
This self-test does not detect faults.
The test is only for checking the revisions of D600, D500 and N500.
24.3 Check EEPROM
Open the phone and check for liquid damage.
No further action should be taken for a liquid damaged unit, send it on according to the
local company directives.
Check R801and R802.
Make sure there is no short circuit against ground at I
2
CCLK or I
2
CDAT, (mainly at the
display).
Also check the resistors R850 and R859.
Power up the board and check VDIG.
Usually the fault depends on D602.
24.4 Check Speech DSP (Speech coding)
Open the phone and check for liquid damage.
No further action should be taken for a liquid damaged unit, send it on according to the
local company directives.
Power up the board and check VDIG and VCORE DSP.
If the voltages are correct, the fault is probably is due to D500.
24.5 Check the PASIC
Open the phone and check for liquid damage.
No further action should be taken for a liquid damaged unit, send it on according to the
local company directives.
Usually the fault depends on N700.
24.6 Check RTC (Real time clock)
Power up the board and check VRTC, measure at C771.
The RTC-frequency can not be measured.
Mainly it is B800 that is faulty, but sometime it is due to C800, C801 or C771.
24.7 Check the ALARMON signal
Open the phone and check for water damage.
The fault can be due to V600 but usually is D600 or N700 faulty.
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