Repair a sticky iris...black screen when taking photos.

Tried almost all the suggestions on the Internet regarding a black LCD screen when wanting to take a photo. Tapping the camera on a desk while extending the lens would have it working for a day. The following day it would not work. Remembered an old HDD trick for failed drives. Place the camera in a plastic bag and put it in the fridge for a good few hours.

Removed it and placed it on top of the warm PSU of the PC for a few hours.

Switched on the camera. Worked 100 %.

Still working 3 weeks later. The contraction and expansion on the iris or whatever was causing the friction solved my issue.