Motorola MOTOTRBO XPR 7550e - Page 53

Troubleshooting Charts 5-23
Figure 5-23.Troubleshooting Flow Chart for GNSS (Sheet 1 of 2)
GNSS no C/No,
no TTFF
DIG_1V8_GPS_
BT
E8002=1.8V
No
Check U8001
U8001.A2=1.8V
?
Check SW3_1.8V
from power
management IC
No
Check U8001
U8001.C2=1.8V
?
No
Yes
Replace U8001
Yes
Reflash SW or check
uProcessor
EXT_LNA_EN
R8004=1.8V?
Yes
Check UBLOX
OTP
No
TCXO_IN
R8006 =
26MHz?
Yes
Inspect TCXO
TCXO_IN
within phase
noise limit?
Yes
No
No
TCXO_IN
within phase
noise limit?
Yes
Measure spectrum after
diplexer = ref - 2.1dBm
Yes
Inspect diplexer
FL8000
No
A
No
Yes