[Kenwood] TS950SDX stuck in transmit mode

[Peter Ravn]

Since November my TS950SDX has been stuck in transmit mode with no output at

all. To test the T/R antenna relay I had applied 12 V to the relay from an

external PS without unplugging the connectors to the filter board, which of

course was unwise. When I switched on the radio again, the transceiver was
stuck

in TRANSMIT mode without any indication of output. When the AT was engaged,
the

SWR on the internal meter would run out of scale. There was no indication of
Ic

on the internal meter no matter the mode.

 

After a long search I found a shorted transistor (Q152) in the TRX sub

board (X59-3680-00) in the control unit. The short was suspected to have
been

caused by the above mentioned blunder.

 

Today the board was taken out and the shorted transistor replaced. Before

mounting the board, I tested it to see if it would switch between RX and TX.
It

did. But when the board was reinstalled, the TS950SDX was still stuck in

transmit mode with no output, so apparently the problem is somewhere else.

 

Any idea will be appreciated.

 

Thanks.

 

73 Peter

OZ8CTH