Symptoms
- Receiver powers on then shuts off within seconds
- Display shows 'Protect' or a blinking indicator
- Happens right after connecting new speakers or wires
- Happens after extended loud use
Likely causes
- CommonSpeaker wire short (bare strands touching)Exposed positive and negative wire strands touching each other trips protection instantly.
- CommonImpedance mismatch from speakersWiring speakers in a way that drops below the receiver's rated impedance (e.g. wrong series/parallel setup) overloads the amp.
- PossibleOverheating from poor ventilationStacking the receiver in an enclosed cabinet blocks its cooling.
- PossibleInternal component failureA failed output transistor or capacitor can trigger protection with no external cause.
- Less commonHDMI or subwoofer output issueSome receivers trip protection from a faulty connected component drawing excess current.
What to do
- Power off and unplug the receiver, then disconnect all speaker wires.
- Inspect each speaker wire end for stray strands that could touch the opposite terminal, and re-trim/twist them cleanly.
- Plug in and power on with no speakers connected; if it stays on, the amp itself is fine and a speaker/wire is the cause.
- Reconnect speakers one pair at a time, powering on between each, to find which one trips protection.
- Confirm speaker impedance (4, 6, or 8 ohm) matches what the receiver supports, especially with multiple speakers per channel.
- Move the receiver to an open shelf with a few inches of clearance on all sides and above.
- If it still trips with no speakers connected, stop using it and have it serviced.
Tools and parts
- Wire strippers
- Small screwdriver
When to call a pro
If protection mode continues with speakers disconnected, the amplifier section needs professional diagnosis and repair.
Safety
Use caution
Always unplug the receiver before touching speaker wire terminals to avoid shock or damaging the amplifier further.