FRIENDCOM FC-301/D User Manual - Page 13

Browse online or download pdf User Manual for Measuring Instruments FRIENDCOM FC-301/D. FRIENDCOM FC-301/D 14 pages. Rf link module

Print Page

SYMPTOM S

Unit does not work

Bad RX Sensitivity

Defective RX

PLL Error

Low TX Power

No TX Power

No Modulation

TROUBLE SHOOTING GUIDE

CAUSES

1.No

power

connection

2. No input voltage of 5V or 8V

3. CPU does not work

4. EEPROM fail

5. Channel error

6. PLL error

1.Antenna signal short-circuit

2.Antenna signal open-circuit

3. Bad

electronic turner

4. Defective high frequency

amplifier

5. Bad mixer

6. Local signal amplitude

become small

7. Bad 1

and 2

frequency

1. No output signal

2. Bad signal waveform

3. Bad stability of VCO

1. TCXO frequency error

2. Bad stability of VCO

3. PLL can't be locked

1. Bad amplifier circuit

2. Bad APC circuit

1. No power on TX

2. No signal on driver

3. Bad amplifier circuit

4. Bad APC circuit

1. No input signal

2. No TX signal

COUNTERMEASURES

incomplete

1.Check COM1 connection

2. Check IC500、IC504

3. Check IC510

4. Check IC502

5. Check CF3

6. Check TCXO、VCO、PLL IC

1. Check D106 D107

2. Antenna loose weld

3. Check L23 L24 L25 L26

4. Replace Q15

5. Check IC3 T3 T4

6. Check D103 Q111

7. Check XF1 XF2 IC2

intermediate

1. Replace IC801

2. Check U2 c412 c404

3. Check component of VCO

1.Check crystal oscillator of TCXO

2.Check

TX/RXVCO

3. IC301 Q321 Q320 C327

1. Replace IC102

2. Check D102 IC1

1. Check Q502 Q503

2. Check Q1 Q2 D101

3. Check IC102 D102

4. Check IC1

1. Check IC801

2. Check U1 R403 R404

- 12 -

the

component