Raymarine RAY230E Owner's Handbook Manual page 120

5-8
Item No. Item No.
Item No. Item No. Item No.
7
No receiver (All
Channel Receiver)
Or low sensitivity
8
SQ circuit
inoperative
9
PLL inoperative
Symptom Symptom Possible Cause Possible Cause
Symptom Symptom Symptom Possible Cause Possible Cause Possible Cause
a.Check RF PCB as follows:
1) +R8v line: Q30 output
2) BPF control voltage (Vcp): pin 12 of
J2, pin 7 of IC8, CH16: 2V, WX0:
4.8V
3) VCO frequency: f-21.6 MHz
4) VCO output level: 775 mV typ.
5) Mixer input: G2 of Q19
6) 1st IF output: Q20
7) 21.145 MHz Xtal OSC
b. Defective/device:
ANT SW diode: D1-2
BPF tracking: Vcp
PLL circuit
Q14, Q16-20, Q30, D9, D11-16
a.Check SQ circuit on RF PCB and CPU
PCB as follows:
1) Busy1 noise output: pin8 of J2,
pin14 of IC7
2) DC amp out: pin7 of IC314, pin97
of IC305
3) SQ VOL IC output: pin6 of J2, pin10
of IC13
b. Defective/device: IC7, IC312-314,
CPU (IC305)
a.Check at DC power source:
1) +6v line: IC14 output
2) +5v line: IC13 output
3) VCO B+ (5.3V): (Q8 output)
b. Check 12.8 MHz Xtal OSC (X1)
c. Check T/R SW voltage (VCO T/R):
RX : 0V TX: 5V (pin 13 of J2)
Maintenance