RF and EF extenders on the EF 600/4L IS II

neuroanatomist said:

Looks like he used the control ring version of the adapter, did you use that one or the vanilla one? I used the vanilla one and like you, I had to trim it back sufficiently to expose the PCB (see this post from earlier in the thread). I did cover the opening with electrical tape.

Click to expand...

That is quite correct. I've done both and the plain adapter exposes electronics and the control ring one doesn't. My plain adapter also missed springs behind the pins and thus relied on pressure from circuit board to make contact. That was not reliable at all. That may have been assembly error or they changed it after that as someone wrote later that his plain adapter had springs.