Ericsson R250s PRO Troubleshooting Instructions page 16

4.1.5 The hands free can not be detected
Check visually the system connector of the phone (if its damaged, dust...).
Disassemble the phone and check for liquid damage, especially at the system connector-pads.
No further action should be taken for a liquid damaged telephone.
Check the soldering of D600, pin67 and pin70.
•
Measure the resistance of R636 ~22 kohms, R635~22 kohm, R601~1 kohm and
R605~1kohm.
If it does not help, send the unit on according to the local company directives.
4.1.6 Microphone and earphone problems
Check visually the system connector of the phone (if its damaged, dust...).
Disassemble the phone and check for liquid damage, especially at the system connector-pads.
No further action should be taken for a liquid damaged telephone.
Check the soldering of D600, pin67and pin70.
•
Measure the resistance of EXTAUD to ground. It should be >10 kohms.
•
Measure the resistance of PORTHF to ground. It should be >10 kohms.
•
Measure the resistance of R636~22 kohms, R635~22 kohmsR601~1 kohm
and R605~1 kohm.
Noisy sound
Disassemble the phone and check for liquid damage.
No further action should be taken for a liquid damaged telephone.
Give the board power and start it up.
•
Measure VDIG at C600 and VDSP at C900, both should be 3,2V.
•
Measure VDSPC =2,5V, at R727.
4/00021-2/FEA 209 544/18 D
Replace the faulty component.
If the fault remains, replace D600.
If the resistance is lower than 10 kohms, replace F600.
If the resistance is lower than 10 kohms, replace F602.
Replace the faulty component.
If the fault remains:
Replace D600.
If it does not help, send the unit on according to the local company directives.
If one of the values is incorrect, go to section On/ Off problems.
If the VDSPC is low, switch off the board, measure the resistance between VDSPC
and ground.
Standard Trouble Shooting Instructions
16(35)