Manual | Jbl Rma 220 User

The manual points out the illuminated rings around the power and volume knobs, which change color to indicate signal status or clipping (distortion). Ease of Setup

| Problem | Likely cause | Fix | |---------|--------------|-----| | No power | AC cord, fuse, or power switch | Check IEC, replace fuse (same rating) | | No sound, LEDs dark | No input signal | Check mixer/processor output | | Sound distorted | Mode switch wrong (bridge with 4Ω load) | Change to stereo or increase load | | Hum / buzz | Ground loop | Lift signal ground using XLR pin 1 lift switch (if available) or use DI box | | Amp shuts off mid-show | Thermal overload | Reduce level, improve airflow | jbl rma 220 user manual