Lens ER...clean contacts?

My stm 70 -250 lens is getting an error and only when zooming more than 200. I forget the error code but it said something about cleaning the contacts.

I inspected them and they all look good and even wiped it with a dry microfiber cloth. I also wiped my camera contacts as well.

Thing is the lens works fine except for anything anything higher than 200 zoom.

My 18 to 135mm works perfectly fine.

How do I clean the contacts?
What else could be wrong.

Camera and lens were not dropped. Lens was working minutes prior too even at 250mm

More testing but if I have aperture wide open 5.6 and full zoo. At 250mm it works. If I start closing down aperture I get the error.

Educated guess: It's your flex cable.

A common fault with EF 24-105 as well as some other lenses.
I never heard of it with 55-250 IS STM, but googling "55-250mm IS STM flex cable fault" indicates it does happen.

It's a cable inside the lens that gets worn out from use as it has to flex as you zoom.
You get 'clean contacts' error message as a broken flex cable causes the same sympton: no communication between camera and lens.

Choderboy wrote in post #19241632
Educated guess: It's your flex cable.

A common fault with EF 24-105 as well as some other lenses.
I never heard of it with 55-250 IS STM, but googling "55-250mm IS STM flex cable fault" indicates it does happen.

It's a cable inside the lens that gets worn out from use as it has to flex as you zoom.
You get 'clean contacts' error message as a broken flex cable causes the same sympton: no communication between camera and lens.

Thank you for this information on flex cable. I cleaned my contacts and it must be the flex cable being the issue.
It seems that at/beyond a certain zoom (almost 200) and ANY f stop greater than 5.6, I get the fault. I can zoom to any setting full open at 5.6 fine.

I will have to hunt down a replacement lens. This lens, a very cost effective lens, is very sharp and good to have in the bag.

I was talking with a lens repair guy just last week. His first question was if the lens was a first gen, or 2nd/3rd. He said Canon no longer sells parts on 2nd/3rd gen lenses so those need to go to Canon for repair. I was inquiring to have just the front element removed so he made it clear that he would take no responsibility if the FRAGILE and THIN current ribbon cable snaps.