- If you do not know what you are doing, STOP! This is not a job for impatient person that would rush the process. Go online and look at some videos what it takes to do it. Sometimes it takes 1 min sometimes it takes 30 min.
- Never use a blower inside the sensor chamber. You can bend your curtain, you can move the dust inside the camera optics and so on.
- Never use a cloth inside on the sensor as it will 100% leave more dust than what you had before.
- Never use brush to clean the sensor. Brush just like cloth will leave more dust than you originally had.
- If you are using liquid make sure you read very carefully if you can use it on your sensor and most likely I would advise you not to do it.
- Sensor vacuums does not work. Period - been there, done that.
- The tool you are using to clean your sensor needs to be soft so it does not scratch the surface.
- The tool you use to clean the sensor needs to be used only for the sensor. Do not clean your lens with it as it might have oily substances and then that would go to your sensor.
- Make sure your tool or process will not leave oil residue on the sensor glass.
- Do not apply any pressure - we are removing dust not rocks.
If you have the money and time send it to your local authorized service shop. Leica would cost you somewhere between 450-750 Euros. Sony, Canon, Nikon will definitely be cheaper but it will be expensive no matter what. But on the other hand if you damage your sensor or curtain it will cost you way more so think about the risk. Leica USA would most likely send you a loaner while the rest will not. Some years ago I had to send my Leica M body and 50mm Summilux to Leica USA for fixing the focus on the lens itself. They did a phenomenal job repairing the lens, plus they sent me a loaner with overnight shipping! This my friends is worth a million so Leica service is one of a kind.
Good Luck in your sensor cleaning adventure.