Canon’s explanation of the Err01 is “Communications between the camera and the lens is faulty. Clean the lens contact.” Well, life can’t be that simple can it?
I’m sure there are cases where the lens contacts are indeed dirty enough to interfere with communication between the camera and the lens. There are lots of cleaning tips online including the ‘pencil eraser’ method. If that worked for you consider yourself lucky.
Here is the dreaded Err01 message:
No amount of cleaning, resetting and swearing was going to make the error go away on this Rebel XTi. I’ve also verified that it wasn’t the lens, dirty contacts, or the firmware. So I decided to take a deeper look (literally) to see what is really wrong.
It turns out that the internal connector pin that connects the lens contact pin assembly to the circuit board has burnt out! Yes, burnt. The connector was covered with green fungus-like powder and some gooey substance was underneath it. And there were black burn marks on the flexible strip.
Holy crap! how could have this happened? My two guesses are:
A. There were excessive moisture/humidity build up along the contacts while the lens was being removed with the camera powered on. (very unlikely, but a theory nevertheless)
B. The lens motor overloaded the camera. Perhaps, this poor XTi was trying to auto-focus a huge lens for prolonged period of time and/or there were constantly higher than normal resistance from the lens barrel from your hand being in the way, etc… (very likely, especially when using non-ultrasonic lnses).
I carefully cleaned the connector with alcohol. But as you can see, few of the connectors are burnt out and has disappeared from the strip. It’s obviously not going to work as is. But I’ve put the camera back together just to see if it behaves any different. Yep, just as expected – didn’t work. The camera throws same error as before.
Now, I either have to look for a donor Rebel XTi that has the pin connectors intact or the part itself. With some luck and careful soldering, I should be able to bring this poor EOS XTi back to life. Fingers crossed and eyes open on eBay! Although, I should probably contact Canon first to see if they can help me locate the part.