Ericsson R250s PRO Troubleshooting Instructions page 12

•
Check the amplitude of the 13MHz system clock at B510 pin 1 ~1V t-t.
Measure it by using an oscilloscope, spectrum analyser, frequency counter or diode probe.
NOTE!
If the fault still remains send the unit on according to the local company directives.
3.6 The phone does not start after flash programming
Disassemble the phone and check for liquid damage.
No further action should be taken for a liquid damaged telephone.
Make sure the system connector pads are not damaged or burnt.
•
Measure the resistance of R421 ~0.1 ohms.
Mount the board in the fixture. Start it up and keep it running by keeping DCIO high.
•
Measure VDIG-N702 pin5 and VDSP-N701 pin5 voltage ~3.2V.
•
Check the power reset (PWRRST) voltage at C710 >3V.
Make sure there are not any faulty soldering at D600 or D610.
If it looks good, replace D610 first and then D600.
NOTE!
4/00021-2/FEA 209 544/18 D
If the amplitude is too low, send the unit on according to the local company directives.
Make sure there aren't any faulty soldering at D600 or D610.
If it looks good, replace D600 first and then D610.
Do not replace any of the components unless you have established the fact that
B510 is functional. Try programming the phone in between.
If R421 is replaced, the charging function has to be verified. If it is incorrect, send the
unit on according to the local company directives.
If any of the voltage is too low, measure the resistance from it to ground (VDIG - >500
ohms, VDSP - >25 kohms).
If the resistance is correct, replace the corresponding circuit.
If it is too low, send the unit on according to the local company directives.
If any of the voltages are too high, replace the corresponding circuit.
If it is less, measure the resistance of R704 ~0 ohm and R725 ~100 kohms.
If they are correct, replace C710first and then N703.
If that does not help measure VRAD-N412 pin5, VVCO-N410 pin5 and
VRPAD-N411 pin5 voltage ~3.8V.
If any of the voltages are incorrect, measure the resistance from it to
ground (>50 kohms).
Program the phone in between.
If the resistance is correct, replace the corresponding circuit.
If the resistance is too low, send the unit on according to the
local company directives.
Standard Trouble Shooting Instructions
12(35)