Motorola MTH500 Service Manual page 64

Troubleshooting
Check E201
for opening
Yes
3 - 14
DC Distribution (V5_RF/PWM1/VSIM1 _5.6V) Test and (VSIM1) Test
Use these tests on a unit with the following symptoms: no V5_RF, no PWM1_5.6V,
or no VSIM1_5.6V.
PWMI
Check C615, C651
for 5 Vdc
Yes
Is the voltage OK?
No
Disconnect E201
Is the volt age OK?
No
Check C623
for 5.6 Vdc
Yes
Is the voltage OK?
No
Check L600, C601
for 3.6 Vdc
No
Is the voltage OK?
Yes
Refer to the
DC distribution (V2_2.775 V)
Test flowchart
Yes
Check trace till
C24, C406, C403
Replace U600
(GCAP III)
Replace L600
VSIMI
Check VSIMI C652
for 3.0 Vdc
Is the voltage OK ?
No
Check U601 pin 3
for 2.775 Vdc
No
Is the voltage OK?
Yes
Check U601 pin 1
for 5.6 Vdc
No
Is the voltage OK?
Yes
Replace L601
68P02963C70-O