Canon 200mm f/1.8L (spares/repair)

[Dawid Loubser]

Hi,

Apparently, none of the following parts (autofocusing unit) are available for the 200mm f/1.8L anywhere in the world - is this the case? What does one do when your USM motor goes?

CY1-2290-000
CY1-2710-000
CY1-2794-000

(I don't own this lens, but I did a general inquiry with Canon, and I'm very curious what the owners of this lens will do once their autofocusing dies, which seems to be not-too-uncommon)?

Is there *any way* to repair, for example, a USM motor (assuming an electronics expert)? I'd love to know a bit more about this.

 

[Deleted member 55]

Hi Dawid.

The thing to remember is that what You hear from Canon is the Canon party line.

A good friend of mine had canon say that his 400-mm f2.8 mk1 was not repairable (bad USM) to have a authorized service center repair it.

The 200 f1.8 is from a series (200 f1.8, 300 f2.8, 400 f2.8, 500 f4.5, and 600 f4 all non IS) that have many common parts assys. This means many possible junk yard donors.

The most likely parts to fail in the USM motor are the capacitors on the flex controller board. The hardest thing is knowing how to get it apart. A good service shop will have no problem with this.

The most likely problem is cold solder joints caused by vibration from use or the ultra sonic vibration it's self. The fix a hot air reflow of the controller board is a pretty simple operation. (I have 100 pin surface mount CPU in portable units that I have to do this to on a regular basis (in & out of warranty) due to hi vibration from having a speaker mounted on top of it)

 

[Dawid Loubser]

Thank you Will, I would also have imagined that, in principle, electronic components should last longer than purely mechanical ones, as long as one has the capability to replace individual components, or re-solder their joints.

A USM motor has, to my understanding, almost no moving parts (being basically two rings driven by vibration) and should not easily fail?

I guess it all comes down to having service people with good enough electronics skills. Ons last question - is the USM motor itself in the 200 1.8L unique to that model (and, as far as I know, the 50 1.0L also used the same motor) or did any other models use the same one?

 

[Deleted member 55]

Dawid, I only have a parts list for the 200 1.8 and the 600 4.0.

The following parts have the same number:

Converter, DC/DC (I believe to be the USM power source)
FPC ASS'Y (I believe to be the Focus PC board)
Power Diaphragm Unit
PCB assy, Relay
Focus Contact Unit
Preset Switch Unit
Switch slide 1
Switch slide 2
Contact R
Contact L
Tripod Socket
Contact Assy
Knob
Holder, Ball
Spring, Coil
Stopper, F.P. Ring
Spring Plate
Nut, Lock
And so on.........................

CY1-2798-000 D 1 FOCUSING UNIT (New) FOR EF 600mm 1:4.0 L USM
CY1-2794-000 D 1 FOCUSING UNIT (New) FOR EF 200mm 1:1.8 L USM

The reason for the difference is that the focus cam for 200mm is different from 600mm!
The motor is still the same but sold as an assy.

 

[Paul Bestwick]

I can't comment specifically on this lens but I can tell you that when I worked for Canon service we had plenty of units returned to the sender unrepairable due to lack of parts. As each year passes the list grows.
Bottom line is that they don't manufacture parts indefinitely.
(a few great cameras for example, F1, NF1, T90)
Cheers,

Paul

 

[Deleted member 55]

we had plenty of units returned to the sender unrepairable due to lack of parts.

Hi Paul, My point is that this is a corporate decision not an absolute.

I had canon say this to me on my 200 f1.8 when I asked them to clean it, it was working excellent at the time just had condensed lubricant on the elements that looked like Armor-All on the front elements. I said I only asked to have it cleaned, they cleaned it and it works just fine.

Most factory repair centers fallow a strict company policy that says replace the whole assembly since they do not sell sub assemblies even tho a good tech can repair or swap a sub assemblies and make it as good as new.

I do not believe that Canon conducts component level circuit board repair at their EOS repair facilities in the US.

A good repair shop has a bone yard of old bad major assemblies and dead units to scavenge from when desperate.

It is kinda nice to not be a consumer repair facility, You do not have to return every replaced bad part.

We commonly save replaced bad logic boards where it is not cost effective to repair but when that board is no-longer available customers thank us for the old ones that we then repair at the customers request then use.