5-21
Flow Chart of Troubleshooting and Circuit Diagrams
5-13 DCS Receiver
Rx On
RF input : CH center freq. + 67.7 kHz
Amp. : -50 dBm
U605
Pin 8
≥
-50 dBm
U605
Pin 1
≥
-53 dBm
U500
Pin 1
≥
-53 dBm
U502
Pin 17, 18
≥
-58 dBm
U502
Pin 1, 2
≥
50 mV
U503
Pin 2, 3, 4, 5
> 100 mV
Resolder
U604
Check
VC1 : L
VC2 : L
Check
Ant. s/w
control
circuit
Resolder
C617, L603
Resolder
U500, C502, C503, L500
Resolder
U401
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Yes
Check
U502
Pin 12, 13
(Freq-100KHz)
≥
-6 dBm
OK?
No
Resolder
U605
Check
U502
Pin 14, 23, 26, 31, 32
> 2.7 V
OK?
Resolder
U503
No
Yes
Yes
No
Check
U503
Pin 14, 16, 17, 18
OK?
Check
U503
Pin 7, 20
OK?
No
Check
Radio PSU,
RF13MHz part
Yes
No
Check & Resolder
I/O signal, RF13MHz, RF PSU Part
Resolder
U502