Error err30 occurred in Canon 5D2.

1. First, switch the power supply or reinstall the battery according to the prompt, and confirm whether this method can cancel the error report.

2. If step 1 doesn't work, we can change the lens and repeat the above steps.

3. If it still doesn't work, we can remove the camera lens, accessories (mainly the handle) and battery and put it in a dry, ventilated and sunny place for three or four hours to a day (ERR30 often appears because the camera is wet).

4. After standing, we will put the lens and battery back and turn it on to see if the situation has eased. (Sometimes ERR30 disappears at this point. )

5. If ERR30 is still prompted, we can take off the lens (pay attention to dust prevention), then enter the menu and choose to manually clean the sensor. Now observe whether the shutter can be opened from the bayonet. If the shutter does not open at this time, please send the camera to customer service. If the shutter is successfully opened at this time (it may be opened once and then closed quickly), please turn off the power and take out the battery. (I didn't use the switch to turn it off at this step, but I pulled out the battery directly. )

6. Install the lens, reload the battery and start the machine. If the mistake disappears, congratulations, you can save a lot of money. If the ERR30 is still being repaired, please also send the camera to the customer service department.