Ericsson R320s Working Instruction page 22

Trouble Shooting Guide, Standard
Measure the VRAD voltage at C501, at the side close to N700 (3.80 V).
If the voltage is incorrect, send the unit on according to the local company directives
Measure the V380B voltage at C500, at the side close to C421 (3.80 V).
If the voltage is incorrect, send the unit on according to the local company directives
Measure the VVCO voltage at pin 5 of N502 (3.80 V).
If the VVCO voltage is correct, go to section 2.2.1.
If the voltage is incorrect, measure the voltage at L500 (3.70 V), at the side close to C503.
If the voltage at L500 is correct, measure the voltage at V500, at the side close to N700. It
shall be more than 4.10 V.
If the voltage at V500 is correct, measure the voltage at pin 1 of N502, it shall be more than
4.10 V.
If the voltage at pin 1 of N502 is incorrect send the unit on according to the local company
directives.
If the voltage at pin 1 of N502 is correct, measure the voltage at pin 3 of N502 (3.80 V).
If the voltage at pin 3 of N502 is correct, replace N502.
If the voltage at pin 3 of N502 is incorrect send the unit on according to the local company
directives
If the voltage at V500 (at the side close to L500) is 3.70 V, replace V500, otherwise send the
unit on according to the local company directives.
If the voltage at L500, at the side close to C503, is incorrect, measure the resistance of L500
(0 ohm).
If the resistance is correct, send the unit on according to the local company directives
If the resistance is too high, replace L500.
2.2.1 Check the feed voltages
The VRAD voltage for N234:
Measure the voltage at pin 5 of N234 (3.80 V).
If the voltage is incorrect, measure the resistance of L211 (0 ohm).
If the resistance is incorrect, replace L211.
If the resistance is correct, measure the resistance from one the sides of L211 to ground (2
Mohms).
If the resistance from L211 to ground is incorrect, replace C214, C211 and C212.
Measure the voltage at pin 47 of N234 (3.80 V).
If the voltage is incorrect, measure the resistance of R345 (18 ohms).
If the resistance is incorrect, replace R345.
If the resistance is correct, measure the resistance from pin 47 of N234 to ground (2Mohms).
If the resistance from pin 47 of N234 to ground is incorrect, replace C345 and R345.
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