In this short entry we show how we fixed what seems to be a fairly common issue with Yaesu’s G-1000DXC azimuth rotor controllers.

The problem was that the front panel of the controller was unresponsive. After opening the chassis to diagnose the fault, we discovered that the primary side of the mains voltage input transformer had become open. Several other hams also report similar issues, which leads us to believe that the problem stems from a fairly common event such as voltage spike or current surge. Further, the input has no clamping against such faults, so damage is likely.

The faulty input transformer, marked KT-28-E-3.

The fix is to simply replace the KT-28-E-3 transformer. A transformer that converts from mains to 16 V AC for the electronics, and 28 V AC for the motor will do the job. Our solution was to reach out to WiMo and hear if they had some spare parts in stock, and luckily they did. Other alternatives include salvage, or attempting to repair/rewind the original core.

The transformer is accessed by removing the top lid and the electronics board. These are fastened with screws on the upper back of the rear panel and the front of the top panel. Further, the connectors to the electronics board must be temporarily detached.

We elected to attach the new transformer in the laziest conceivable way, by using wago 221 wire clamps on stripped cables.

Cable ties installed, connectors reinserted.

With everything re-assembled, all that remains is to test that is functions properly.

Success!