Kenwood TR-7625 Service Manual page 20

TROUBLESHOOTING
2. TRANSMITTER SECTION
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No transmitter output.
1 . Check if rotary switch is stopped between contact.
or abnormal power. 2. See troubleshooting for the PLL circuit.
1 . Rx-Tx unit power supply circuit is defective
ON AIR lamp
(check T9 term~nal).
2. Check 0 2 6 - 2 9 in TX-RX unit.
\ /
(
3. check C9, T9, FTB terminal voltage in Tx-Rx unit.
1
Abnormal
RF
meter
1. Check antenna cable connection.
deflection.
2. Check inner wiring of antenna connector.
Little or no deflection
Meter malfunction.
No voltage
1. Check TP1 level TX-RX unit.
T P 2 a n d Q1O1 i n the 2. Check power supply voltage.
3.
Check PLL output level.
About 2.1W 1. Check whether meter lamp is Ilt green
(
Power
> - 4
2. Confirm HI LOW switch setting.
0 K
No LOW POWER
1. VR4 adiustment TX-RX unit.
Almost no power
1. Microphone defective or poor plug contact.
Insufficient o r n o
No sound 2. IC or VR defective i n MIC amplifier.
Monitor sound quality 3. Poor contact at VR1. VR2 in TX-RX unit.
4. Modulator circuit Power supply defective.
(check power supply.)
1. Antenna changeover diode (check D7 and D8.)
2. Check 0101. FIB. DRB terminal voltage in Rx-Tx
unit.
-
Low Mod.
1. VR1. VR2 adjustment deviation In Tx-Rx unit.
2. Microphone defective.
3. Check power i s present.
4. Check 0 1 voltage in Tx-Rx unit supply to modulator
circuit.