Canon 6D Mark II Error 20: What It Means & Fix
Error 20 on the Canon 6D Mark II signals a mechanical malfunction that blocked the shot. It is not always a worn-out shutter — in this case, a broken drive motor was replaced for a fixed €150.
Symptoms
- "Err 20: A malfunction with the mechanical mechanism has been detected" on the display
- Fast whirring noise of a gear spinning without engaging
- Mirror moving slowly or not completing its cycle
- Camera locks up intermittently during shooting
Canon 6D Mark II error 20 means the camera has detected a mechanical malfunction that stopped the shot — and contrary to what you will read almost everywhere, it does not automatically mean your shutter is dead. It is fully repairable at a fixed price: in the case study below, the real fault was a broken drive motor, replaced for €150.
The symptoms
The camera in this case had a couple of years of amateur use when it suddenly stopped working. During shooting, the owner would cyclically hear a gear spinning very fast without engaging anything. The mirror was not moving correctly — it looked slowed down — and the camera would lock up, showing "Error 20" on the display. On Canon bodies, Err 20 signals a mechanical error that prevented the shot from completing.
What causes it
Error 20 is generally linked to a malfunction of the shutter, and the standard fix is a shutter replacement. But that is not the whole story. The same error can be produced by the power board — which, if faulty, feeds the shutter assembly incorrectly — or by the drive motor inside the shutter and mirror mechanism. On this camera the shutter count was remarkably low, under 10,000 shots, which made a worn-out shutter very unlikely from the start. The actual culprit turned out to be the internal drive motor, which had failed completely.
Can you fix it yourself?
There is little to try at home: remove the battery, remove the lens, restart. If Err 20 comes back, something mechanical has genuinely broken, and diagnosing which of the three candidate components is responsible — shutter, power board or drive motor — requires opening the camera and testing each one. That is not user territory. A proper diagnosis also protects you from paying for a shutter replacement the camera may not need; it is worth sending the body to a Canon repair specialist.
How we repair it
A customer shipped us his EOS 6D Mark II with the symptoms above. Our practice is to test every hypothesis before replacing anything, and this repair took longer than expected precisely because the obvious suspects were innocent. With the camera fully disassembled, the shutter tested as working perfectly — it was not the cause. The power board, second on the list, also worked flawlessly. By elimination we moved to the mechanism inside the shutter assembly that drives the shot and the mirror movement, and there it was: the internal drive motor, completely broken.
We replaced the faulty motor and the camera immediately returned to normal operation — no more Error 20. The targeted repair also saved the customer money compared with the full shutter replacement he had been bracing for. As always, we tested all other components against factory specification before returning the body.
Price and turnaround
| Service | Price |
|---|---|
| Shutter drive component replacement (Error 20 fix) | €150 (fixed) |
| Internal cleaning | Included |
| Final test & general check | Included |
Typical turnaround is 7 working days from arrival at our lab, plus return shipping at a €20 flat rate anywhere in the EU.
Ship your camera from anywhere in the EU — diagnosis is free, the price is fixed before we start, and the repair carries a 6-month warranty. Here is how it works.
Frequently asked questions
What does Error 20 mean on the Canon 6D Mark II?
Err 20 indicates a mechanical malfunction that prevented the shot. It is generally linked to the shutter mechanism, but the real culprit can also be the power board or, as in this case study, the drive motor inside the shutter and mirror assembly.
How much does it cost to fix Error 20 on a Canon 6D Mark II?
In this case the faulty drive component inside the shutter assembly was replaced for a fixed €150. Diagnosis is free, so you know the exact cause and price before we start any work.
Does Error 20 always mean the shutter needs replacing?
No. The standard assumption is a worn shutter, but on this camera — with fewer than 10,000 shots — the shutter tested perfectly. We check every hypothesis before replacing parts, which here saved the customer money over a full shutter swap.
Can I clear Error 20 myself?
You can try removing the battery and lens, then restarting the camera. If the error returns, a mechanical part has genuinely failed and the camera needs to be opened by a technician.
Is the Canon 6D Mark II worth repairing?
Yes. It is a capable full-frame body, and a fixed €150 mechanical repair is small compared with the cost of replacing the camera.
