ERR 20
Canon DSLR Camera
Severity: CriticalWhat Does This Error Mean?
ERR 20 means a mechanical component in the camera has malfunctioned. This usually involves the mirror, shutter, or aperture mechanism. Turn the camera off and on. If it persists, the camera needs professional service.
Affected Models
- Canon EOS Rebel series
- Canon EOS 5D
- Canon EOS 6D
- Canon EOS 7D
- Canon EOS 90D
- Most Canon DSLRs
Common Causes
- Mirror mechanism stuck or jammed
- Shutter blade stuck or slow
- Aperture control mechanism failure in the lens
- Internal mechanical obstruction
- Camera drop damage affecting internal mechanisms
How to Fix It
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Turn the camera off, wait 30 seconds, and turn it back on.
A temporary mechanical jam sometimes clears with a power cycle.
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Remove the lens and check if the mirror moves freely.
With the lens off, look inside the mirror box. Press the shutter button — the mirror should flip up and down smoothly. If it does not move or moves sluggishly, the mirror mechanism is stuck.
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Try a different lens — the aperture mechanism may be in the lens.
If ERR 20 only occurs with one lens, that lens's aperture blades may be stuck.
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If the error persists, the camera needs professional repair.
Mirror and shutter repairs require disassembly and are not DIY-friendly.
Frequently Asked Questions
Is ERR 20 repairable?
Usually yes. Mirror and shutter repairs are common camera services. Cost varies from $150-$400 depending on the model and what failed.
Can a drop cause ERR 20?
Yes. Physical impact can dislodge or damage the mirror, shutter, or aperture mechanisms. If ERR 20 appeared after a drop, internal damage is likely.