Remove the 8 screws from the Digital A unit shield plate. Swing themount toward the right side of the transceiver and allow it to rest on theDigital B unit shield. Remove the 4 screws from the speaker mount.Ĭarefully pull up on the mount and rotate it toward the front panel. It will be necessary to unplug theVS-1 cable from the transceiver. Loosen the round head screw on each side of the front panel chassis.Ĭarefully rotate the front panel forward. Remove the 2 flat head screws from each side of the front panel chassis. Remove the top and bottom covers from the transceiver. Such techniques include using a grounded or isolated soldering tip,avoid touching the pins of IC chips with your fingers, and ground yourself witha wrist ground strap.To remove the socket:Disconnect the power cord and antenna coax. Havingto pry up on the socket means that it is not completely desoldered and willcause the circuit foils to tear.When performing any work on the Digital A board, CMOS handling techniques mustīe observed. When the socket is removed,it is very important to insure that each pin is completely solder free. The board, being double sided, hassolder connections on both component and foil sides. The ROM is mounted on theDigital A unit and is designated as IC2. In addition, units with a serial number of 909XXXX and above do notincorporate a socket.CAUTIONRemoving the socket requires good soldering skills. It should be noted that units between serial numbers701XXXX to 811XXXX and from 903XXXX to 909XXXX are not likely to have thisfailure. If it is found to be intermittent, remove the socket and solder the ROMĭirectly to the board.

The socket should bechecked to insure that it makes good electrical contact with each pin of theROM. 951 (20-1-1989)Intermittent control or display problems that are difficult to correct with thereset procedure may be caused by a faulty ROM socket. This is an optional change and may not be performed under warranty.Time required for this change is 1 hour or less.ġ9-07-1998 TS-940S Erratic displayAuthor: Trio-Kenwood Communication, inc. Put the covers back on the TS-940S and secure them with the 16 case screws.Ĭonnect the antenna and power cord then test the transceiver for normaloperation.

Lower the board back into its original position (don't pinch any wires!) andre-install the 8 mounting screws. Replace C182 and C183 with 0.0022 uf, 50v capacitors. To access the bottom of the board remove the 8 screws that mount the board andheat sink to the chassis (See figure 1.)Ĭarefully lift the board/heat sink fomr the right hand side and pivot ittoward the front of the transceiver.

Kenwood ts 940 serial numbers