In Case Of Difficulty - Kenwood TM-621A Instruction Manual

6-4. IN CASE OF DIFFICULTY
The problems described in this table are failures caused, in general, by improper operation or connection of the transceiver, not by
defective components. Examine and check according to the following table.
Symptom
Indicators do not light and no receiver noise
is heard when the POWER switch is turned
on.
Probable cause.
Corrective action
. Bad power cable or connections.
. Blown power supply fuse.
. Check cables and connections.
. Check for the cause of the blown fuse and
replace the fuse.
No sound from the speaker. No signal can
be received.
No transmitter output
Signals from the SUB band cannot be con-
troled by VOL control.
. Squelch is closed.
. In the wrong position BALANCE key
position.
. With the TSU-6: (TM-621A/721A) CTCSS
is operating.
Weak signal cannot be received.
Display is dark.
No control works.
. Microphone jack is not plugged in.
. Poor antenna connection.
. MUTE is ON.
. BALANCE key is switched to MAIN posi-
tion.
. Turn the SQL control counterclockwise.
2. Readjust the BALANCE key.
. Press the F key and then MUTE/CTCSS key
to turn off the CTCSS.
. Plug jack in.
. Connect antenna securely.
. Press the MUTE key to clear MUTE.
. Set the BALANCE key to center position.
. Poor antenna connection.
. Connect antenna securely.
. Power voltage is low.
. The DIM key had been pressed.
. Check voltage for 13.8 VDC +15%.
. Press the F key and the LOW/DIM key.
. LOCK is ON.
. During A.B.C. operation, being exchanging
the bands each other.
. Set the Lock key to OFF position.
. See A.B.C. Page 18.