Tx Power Trouble(Dcs) - LG -600 Service Manual

5.2.10 TX Power Trouble(DCS)

START
✔ HP8960 : Test mode
700CH, 2level setting ( TCH )
700CH, -60dBm setting ( BCCH )
✔ Spectrum analyzer setting
✔ Oscilloscope setting
VC-TCXO
U212 pin 3 13MHz
Oscillation check
Frequency = 13MHz &
Power >= -5dBm
RF MAINCHIP
U203 pin 9,10,11,12
I/Q Signal check
I/Q Signal >=
DC 1.35V & 0.5Vp-p
LO1 VCO
U210 pin 3
Frequency & Power check
Frequency = 1323.8 MHz &
Power >= -15dBm
Balun
U209 pin 3
Frequency & Power check
Frequency = 1323.8MHz &
Power >= -15dBm
YES
YES
YES
- 32 -
NO
✔ U212 soldering check
✔ U212 pin 4 DC 2.8V + - 5% check
✔ U212 pin 3 DC 1.4V + - 0.1V check
✔ U212 change another same one
✔ U203 soldering check
NO
✔ S/W check
✔ Ulysse-Nausica check
✔ U210 soldering check
NO
✔ U210 pin 4 DC 2.8V check
✔ U210 pin 6 control signal check
( >= 0.7Vp-p )
✔ U210 pin 1 Low Voltage check
✔ U210 change another same one
NO
✔ U209 soldering check
✔ U209 change another same one