Operation Manual

5-8 Maintenance
Item No. Item No.
Item No. Item No.
Item No.
SymptomSymptom
SymptomSymptom
Symptom
Possible CausePossible Cause
Possible CausePossible Cause
Possible Cause
b. Defective/devices: IC702-704, IC706,
IC708, IC711, IC714, Q703, speaker open
7 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
8 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)
9 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)
d.Check VCO control voltage at TP3:
1.5V - 5.5V
No receiver (All
Channel Receiver)
Or low sensitivity
SQ circuit inoperative
PLL inoperative
RAY230_sect5.p65 7/13/2001, 1:43 PM8