Ericsson R250s PRO Troubleshooting Instructions page 25

7.2.1 If the signal of the SIMVCC is low or missing
•
Measure at D601 pin 1~3,2 VDC
7.2.2 If the signal of the SIMCONCLK is low or missing
•
Measure at D601 pin 1~3,2 VDC, if the level is missing or low replace C626, R682, D601.
7.2.3 If the signal of the SIMCONDAT is low or missing
•
Measure at D601 pin 1~3,2 VDC, if the level is missing or low replace C626, R682, D601.
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If the level is missing or low replace C626, R682, D601.
If the level is ok measure the resistance from the SIMVCC-pad to ground. It should be
>2 Mohms.
If it is lower, replace C625, C635, C627 and R683.
If the resistance is ok: Measure with the oscilloscope at D601 pin 4,give the
board power and start it up. Five pulses with an amplitude of 3,4 V will appear
in the oscilloscope.
If yes (pulses) Replace D601and C693
If no (pulses) measure the resistance between D601 pin 4 and D600
pin 72,it should be ~0 ohm.
If the level is ok measure the resistance from the SIMCONCLK-pad to ground. It
should be >2 Mohms.
If it is lower, replace C629 and R627.
If the resistance is ok: Measure with the oscilloscope at D601 pin6, give the
board power and start it up. Five pulses with an amplitude of 3,4 V will appear
in the oscilloscope.
If the pulses are correct, replace D601and C693.
If they are incorrect, measure the resistance between D601 pin6 and
D600 pin 75,it should be ~0 ohm.
If the level is ok measure the resistance from the SIMCONDAT-pad to ground. It
should be >2 Mohms.
If it is lower, replace C630, R628, and R683.
If the resistance is ok: Measure with the oscilloscope at D601 pin5, give the
board power and start it up. Five pulses with an amplitude of 3,4 V will appear
in the oscilloscope.
If the resistance is substantially high, send the unit on
according to the local company directives.
If it is ~0 ohm replace D600.
If the resistance is substantially high, send the unit on
according to the local company directives
If it is ~0 ohm, replace D600.
Standard Trouble Shooting Instructions
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