LG KG110 - Page 43

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4. TROUBLE SHOOTING
Lowband = 32.5dBm?
Highband = 29.5dBm?
Check TX level of
U401 pin 20 or
L411
NO
Change U401
YES
CheckR418,R427,L405,
Check whether Ant SW
Set as TX mode
? Refer to Table 4-3
NO
Change the board
Vmod_en = H?
Vtx = H?
Vbs2 = L?
YES
For the test
TX stand alone mode is needed
Refer to chapter 11 (PL=11 for
GSM, PL=2 for DCS)
~30 dBm?
Check mobile SW port:
SW400.ANT. Check if
signal is existed
NO
Change ANT matching
circuit
YES
END
~ 30 dBm?
Check mobile SW port:
SW400.RF . Check if
signal is existed
YES
NO
Change SW400
Check ANT feed point,
If ANT touch PCB tightly
NO
Press ANT tightly
Tightly?
YES