Rf Signal Weakness Problem (Have No Signal Even) - FLY DS210 Service Manual

5.3.5

RF Signal Weakness Problem (Have no signal even)

RF signal problem
Check RF transceiver（U100）
power supply , and related circuit
Check RF receive path, SAW101
and SAW102 (EMI filter IC) and
related circuit components
Check RF transmit path, U101
(Power amplifier IC) and related
Check RF crystal, U105, its
frequency should be 23 MHz
Check U105 powers and control
signals are ok?
Check antenna
YES
Check antenna path
YES
components
YES
YES
circuit components
YES
YES
END
Antenna is poorly contacted with
NO
mainboard. Replace new Cover D with
antenna
Resolder and replace related circuit
NO
components.
Something is wrong with U100 or related
NO
circuit components. Go to Level 4
NO
Something is wrong with SAW101, SAW102 or
related circuit components. Go to Level 4
NO
Something is wrong with U101 or related
circuit components. Go to Level 4
Something is wrong with U105 or related
NO
circuit components. Go to Level 4
Something is wrong with
NO
U6235. Go to Level 4