william_hester

<p>Following reading <a href="../photodb/user?user_id=5201364">Mitchell Macha</a> , Jun 14, 2009; 04:48 p.m. response (Thanks)<br>

I dismantled again and rotated the retaining ring under the lip as suggested.<br>

This must be the cause and fix, gradual slippage or something and then it dislocates.</p>

<p> </p><div></div>

<p>Thank you very much for this.<br /> It enabled me to fix my lens (EF 20-35 3.5-4.5 USM) and have a working camera.<br /> A Canon repair would have not been economic.<br /> I had the same symptoms (failure to autofocus, followed shortly by failure of manual focus)</p>

<p>Instead the cardboard spacers, I rotated the felt washer and 're-sprung' the wavy spring.<br /> The felt washer ranged between 0.5mm to 0.8mm.<br /> <br /> I had a devil of job removing the black plastic part with the four tabs.<br /> I removed the single screw holding the PCB and then the ribbon cables followed.<br /> This allowed me to more easily pop the four tabs.<br /> (I was considering not removing the black plastic part with the four tabs, but reassembly would have been difficult)<br /> The reason for difficult removal was Loctite holding them.<br /> <br /> I only had 3 black screws retaining the large plastic collar.</p><div></div>