Describe the behavior before opening the equipment or replacing parts.
Safe first checks
Note exactly when the problem occurs and which inputs or controls affect it.
Test with known-good speakers, cables, and a second audio source where safe.
Take clear photos of any visible damage with the unit unplugged.
Stop immediately if you notice heat, smoke, a burning smell, or repeated fuse failures.
Next step
The next version of the diagnosis wizard will collect your description and route it to a tailored troubleshooting path.
Bench Technician Steps
This is the model of work a qualified electronics technician follows using the exact service manual and suitable test equipment. It is not a do-it-yourself instruction to work on energized equipment.
Document the symptom, conditions, inputs, controls, and any visible damage before replacing parts.
Use the exact service documentation for the selected model to form a test plan rather than relying on a similar-looking unit.
If the fault requires work near mains power, stored energy, or live internal circuits, use a qualified electronics technician.