Voxtel VS600, Service Manual

Page: 69 / 83

VS600 Service Manual
VOXTEL Technical Documentation 69
First, set up the corresponding parameters on signal generator and spectrum
en check the readout of different test points on spectrum analyzer. Please
owered off
2. While measuring PCS band, U102 Pin#2 must be provided 2.7V voltage to
Mode medy (if not as expected)
analyzer. Th
be noted:
1. Handset must be p
enable the switch.
Expected value Re
Test point A -64dBm @ 950MHz
Please check/replace U102 or
C133
Test point B -65dBm @ 950MHz
Plea
L131
se check/replace U103 or
EGSM
oint C -65dBm @ 950MHz
Please check/replace C134 or
C125
Test p
Test point D -64dBm @ 1850MHz
C132
Please check/replace U102 or
Test point E
Please check/replace U104 or
-65dBm @ 1850MHz
L132
DCS
Test point F -65dBm @ 1850MHz
Please check/replace C136 or
C137
Test point G -64dBm @ 1950MHz
C127
Please check/replace U102 or
Test point H 0MHz
Please check/replace U105 or
L133
-65dBm @ 195
PCS
Test point I 950MHz
Please check/replace C138 or
C139
-65dBm @ 1
If the symptom is still present, proceed to next session.
Transceiver neighboring circuits.
If front end isn’t the root cause, recommend checking MT6129’s neighboring circuits.
If the faulty is still presen
Pin # Expected
value
#21 2V
(20ms, pulse)
#14 #27 #37 2.8V
#30 #33 #38 2.8V
(20ms, pulse)
#31 26MHz
(V
p-p
≒
800mV)
t, proceed to next session.