topic Re: Canon EF 100-400 IS damaged screw head in EF & RF Lenses

Canon EF 100-400 IS damaged screw head

gustavohn — Thu, 15 Aug 2024 07:49:11 GMT

I recently left my Canon EF 100-400mm IS lens to the only authorized service center in the UAE, for cleaning and fungus removal. However, upon collecting the lens, I noticed that the front element remained dirty, with visible fungus spots still present.

The shop informed me that the fungus issue was located between the lens elements and could not be removed. Additionally, while considering replacing the front element, I discovered that one of the screws had its head completely stripped, which made it impossible to remove or replace the front element.

The screw used in the lens assembly is highly specific, and despite my efforts, I have been unable to find a replacement in the market. Unfortunately, the serivice center has also not been able to provide a positive solution or replacement for the damaged screw.

I have attached photos of the stripped screw for your reference. Have you ever sourced the same type of screw? I hope Canon could support us with it.Stripped head100-400 screw

Re: Canon EF 100-400 IS damaged screw head

shadowsports — Thu, 15 Aug 2024 11:25:34 GMT

Greetings ,

The most important thing here is probably to have the lens serviced in the country where it was manufactured and sold. It's possible that other Canon service centers or parts dept could have the screw, but this is the reason why some service centers can't repair lenses if they were intended for sale in another region. It's not that they don't want to help, but they can't if they don't have the parts.

This might be an "easy out" situation. I'd probably let Canon do the repair because if you break something it's going to be on you. I'd work with Canon as they are probably your best bet given your location.

Re: Canon EF 100-400 IS damaged screw head

jrhoffman75 — Thu, 15 Aug 2024 11:38:42 GMT

If you are going to attempt the work yourself USCamera-dot-com is a possible source for a parts manual and replacement parts.

I'm surprised the center accepted it; it is no longer on the repair list:

Re: Canon EF 100-400 IS damaged screw head

Tonytech88 — Fri, 06 Dec 2024 03:05:36 GMT

Greetings! This is what happens to my canon ef100-400 lens. I strip the 3 screws and it took me more than an hour to extract the 3 screws. I replaced the screw with a new sets. Make sure you use the right Phillips + screwdriver.

Re: Canon EF 100-400 IS damaged screw head

ebiggs1 — Sat, 07 Dec 2024 16:11:55 GMT

IMHO,if you have a problem removing that screw you have no business trying to do the repair.

Re: Canon EF 100-400 IS damaged screw head

shadowsports — Sat, 07 Dec 2024 16:36:58 GMT

Greetings,

My recommendation is always to let Canon perform a repair. I realize this can be challenging when you're talking about a lens that is no longer serviceable. The type of screw is called crosspoint If it helps.

Re: Canon EF 100-400 IS damaged screw head

jrhoffman75 — Sat, 07 Dec 2024 17:02:42 GMT

Actually most Japanese products use JIS, not Phillips head, screws. Using a Phillips screwdriver generally damages the screw heads.