The manual specifies a test point labelled "LOCK". It should be high (3.3V or 5V). If low or pulsing, the VCO is unlocked. Follow the VCO alignment procedure from section 4.2.
is notorious for difficult manual programming, so using a PC is highly recommended: CHIRP Support : Most versions work with CHIRP Next qyt kt7900d service manual
| Symptom | Probable Cause | Solution | | :--- | :--- | :--- | | | Blown speaker or audio amp IC. | Check external speaker jack; check internal speaker connection. | | Low transmit power | Poor power supply or misalignment. | Ensure power supply provides 13.8V under load. Check "P1/P2" alignment settings. | | Cannot program radio | Driver issue or cable fault. | Reinstall drivers; ensure cable is fully inserted. Try "Old Cable" setting in CHIRP. | | High SWR warning | Antenna mismatch. | Check antenna SWR with an external meter. Do not use radio if SWR > 2.0. | | "Clone Failed" error | Radio not in receive mode. | Turn radio off/on and try reading again immediately. | The manual specifies a test point labelled "LOCK"