SERVICE BULLETIN ASB-0167 June 16, 2022WSR Service Code – Information Only - No Warranty Compensation AllowedCopyright © 2022 All Rights Reserved.PO Box 22745Long Beach, CA 90801Tel 310-639-4200TS-890SCircuit update for antenna tuner failure.A TS-890S with confirmed Antenna Tuner Unit (ATU) failure will need to be serviced at the Kenwood authorized servicecenter and a circuit update will be applied to reduce any possible reoccurrence of the ATU failure. This circuit update is not arecall and is not necessary for units that have not had any ATU failures. Only a few isolated occurrences have been noted forthis failure and only units with confirmed ATU failure should have this update applied.If a user of the TS-890S has encountered a failure of the Antenna Tuner, please ship your TS-890S to the authorized servicecenter for repair. Freight charges to the service center will be paid by the user and Kenwood will pay the return freight andperform the repairs at no charge as a courtesy repair, even if the warranty is expired.For users that have already repaired their ATU by themselves and wish to perform this update can follow these instructionsto do the circuit update. No additional parts are required and only 10 chip capacitors are being deleted from the AntennaTuner Unit circuit located on the Final Unit PCB (bottom side).When a TS-890S Antenna Tuner circuit is repaired by replacing the relay control transistors part number DTD113ZU (mainlyQ510, Q511, Q512), please also remove the chip capacitors as follows to prevent recurrence of the ATU failure.Kenwood does not recommend users of the TS-890S attempt any service of its internal components. Only qualifiedtechnicians should attempt any internal repairs. Please ship your TS-890S to a Kenwood authorized service centerfor any needed repairs. Kenwood will not be liable for any damage or injury caused by users attempting to servicethe internal parts of the TS-890S. Anyone attempting to service the internal parts of the TS-890S will do so at theirown risk of causing further damage to the TS-890S or personal injury caused from the service attempt. Anydamage to the TS-890S that occurred while attempting this update will not be covered by the factory warranty orthe courtesy repair.(Instructions)1. Remove all power sources from TS-890 and all external connections from rear and front panels2. Remove upper cabinet lid and RF shield to expose Final/AT Unit PCB3. Remove Final/AT unit PCB from the chassis to expose the circuit update area on the bottom side of thePCB4. Remove 10 small chip capacitors shown in the following picture5. Suggest using 2 soldering irons to avoid damage to the PCB. First apply solder on both sides of eachcapacitor then use both soldering irons at the same time to heat the solder points of the capacitor andmove it from its location6. Caution: If the capacitor is forcibly removed and the circuit trace is torn a repair will be required or theATU circuit will not work7. Check area is clear of any damage and remove any solder bridges / balls8. Re-assemble unit9. Test ATU is operational on all bands