Hi, I know this is a long shot, but does anyone have a copy of the repair manual for this lens?

I have one, but the control board in my lens is different to that described in the manual. It looks like there were several iterations of the older non-IS lens.

The earlier ones seemed to have more flex ribbons and manual adjustments that my lens doesn't have - the shape of the control board is very different.

Anyway, if anyone does have a copy that I could have (pdf or scanned) I would be very grateful.
Maybe someone knows of an independant repair shop that has one?

I will make another plea with Canon, but they seem to be adamant that they cannot help me.

Many thanks.

Hi,
I know that Canon can't/won't help with older lenses - understandable if they have no parts............but why just junk all the repair manuals too?
Perhaps they don't but there is no-one who knows where to look for them - or they cannot be bothered!

Try Lehmanns in Stoke - if the lens doesn't need parts they may be willing to look at it and/or have a repair manual.
What is wrong with your 300/2.8L? - sounds electronics are the problem if you have pulled the main control board.
What shape is the tripod mount foot on your lens?
I'm told, but never been able to verify that there were just two versions of this lens and the only external difference was in the shape of the foot - I'd be interested to compare yours with mine..........if you see what I mean!

Added.

I've done a search of all the Canon stuff I've hoarded electronically.
Guess what?
I have a 300/2.8L repair parts list,
This does say say, 'Old' and 'New' and !st, 2nd.
I therefore presume that New replaced Old as a service part but that 1st. and 2nd. refer to a model change.
If you would like a copy let me know.

Google it, you should be able to find one.

Hi Paul, thanks for your reply. I actually have a copy of both the parts list and the repair manual, and both show references to options for various parts. Some parts have 3 different options.
Maybe there were 2 basic types like you said, but mine definitely has a newer control board than the one described.
This lens its very battered, and it had 2 faults. The AF doesn't work and the aperture didn't. By a complete fluke I found a replacement part to get the aperture working again (the symptom was ERR99), by replacing a small reflective opto-coupler that detected when the aperture was fully open.
Now with the AF, the motor responds but a bit erratically, and I want to check a pulse output from the main board.
Without the correct repair manual I will have to find it by trial and error.
Thanks for the suggestion of Lehman's - I'll try them.

If anyone is interested in the detail of this repair let me know and I'll post some pictures.

Repair manuals are not usually easily available, and especially not from Canon, who are notoriously secretive about such info. The repair manual is like a service manual - not the user manual.
I have Googled it lots but to no avail. If you can do better please let me know.

Is this the main flexboard in your lens ?
If not, then you probably have the older (1st) version of the lens.

http://www.lensinc.net/canonrepair.html
http://4photos.de/camera-diy/index-en.html
http://www.fredmiranda.com/forum/topic/769723

I have a 300 2.8 Non-IS if anyones looking for one! Yeah I got lucky on a few authorized dealers on spare parts..

That's the one! Definitely looks newer than the one in the manual.

Thanks, I'd seen those3. I'm waiting for email replies from the first 2.
Lensinc don't list this lens or any EF lens so I'm not hopeful.

Thanks, I'd seen those3. I'm waiting for email replies from the first 2.
Lensinc don't list this lens or any EF lens so I'm not hopeful.

Thanks, I'd seen those3. I'm waiting for email replies from the first 2.
Lensinc don't list this lens or any EF lens so I'm not hopeful.

!

Hi Mowens, does it still work OK? I'm interested if it's faulty. I enjoy repairing lenses, so I'm always on the lookout for interesting ones to repair.

Would be interested thear how the repairs turn out and details of anything you find with these lenses. I have one, it doesnt need repair but I fear the day it might.

I have the repair manual for 50/1.0L and 85/1.2L , not that it is any help, but just a point of reference. The manuals are out there somewhere, just hard to find.

Hi Ed, I'm sure the repair manual is out there, as you say. The latest with this lens is that I am beginning to suspect the focus encoder. That's a piece of curved glass with bands on it, with a pair of slotted opto couplers that shine light through to measure the focus movement. The photo transistor part of the opto coupler should send out pulses as the bands pass between it and the light source. I suspect that maybe the emitters are not working. Could be interesting to get working if that is the case.
I could really do with the manual to see what I should be checking!

The one thing that is a real pain with this lens is having to un-solder all the flex ribbons each time. There are no plugs and sockets. That makes it reliable but a pain to repair!