Kenwood TM-641A Instruction Manual

Also see for TM-641A: Instruction manual Service manual

@IN CASE OF DIFFICULTYThe problems described in this table are failures caused, in general, by improper operation or connection of thetransceiver, not by defective components. Examine and check according to the following table.Symptom Probable cause Corrective actionIndicators do not light and noreceiver noise is heard when thePOWER switch is turned on.1. Bad power cable or connections.2. Blown power supply fuse.1. Check cables and connections.2. Check for the cause of the blownfuse and replace the fuse.No sound from the speaker. Nosignal can be received.1. Squelch is closed.2. With the TSU-7 :operating.CTCSS is 1. Turn the SQL controlcounterclockwise.2. Press the TONE/T.ALT key to turnoff the CTCSS.No transmitter output. 1. Microphone jack is not pluggedin.2. Poor antenna connection.1. Plug jack in.2. Connect antenna securely.Weak signal cannot be received. Poor antenna connection. Connect antenna securely.Display is dark. 1. Power voltage is low.2. DIM had been set too dark.a . voltage for 13.8 VDC +150.2. Press the F key and the LOW/DIMkey. See page 52.No memory back up. Backup battery voltage is low. See Microprocessor memory backuppage 29Clock is wrong. Backup battery voltage is low.Backup switch is off. Contact the authorized dealer.See memory backup page 8The display does not change whenthe tuning control is rotated.1. The LOCK function is on.°2. The ALL LOCK function is on.621. Press the F key, then press theMHz/LOCK key within 10 seconds.2. Hold down the MHz/LOCK key,switch the power on, then performstep 1 again.