4. TROUBLE SHOOTING
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START
(1) Check the 12V
voltage(TP1)
Yes
No
Check soldering CN100
(DC-Jack) or replace
START
(2) Check the 12V
voltage(TP2)
(3) Check TP3 is high?
No
Check soldering
Q1 & D1
Yes
No
Check the BCM boot
up or not
Yes
(4) Check the TP4
TP4= 5V
Check the soldering
Q101, R124
No
Yes
Yes
(4) Check the TP5
TP5= 3.75V
Check the soldering
U1. If soldering is fine,
replace U1
No
(4) Check the LTE
module connection
Reassemble the LTE
module or replace
CN300 & LTE module
No
FINISH
Yes