EF-S 17-55 f/2.8 IS USM - AF will not lock

Just wanted to put this information out there in case someone is searching for an answer to their dilemma.

I purchased a new Canon EF-S 17-55 f/2.8 IS USM lens about 5 years ago. It is my work horse lens and does a superb job.

However, a couple of months ago I encountered an issue with the AF not being able to lock focus. Daylight, room light, high contrast scene, low contrast seen, IS off, IS on, using a tripod or not, the AF would continually hunt whether I was shooting my EOS 7D, or EOS 7D MkII. This was an on/off again thing so it was not constantly happening, but was aggravating when it did. I worked around it once in a while by simply turning the AF off and manually focusing.

Well, I sent the thing off to the Canon New Jersey, USA repair center and got it fixed for a mere US$ 234.00

So, if you're out there wondering why your lens will not lock focus and how much it will cost to repair it, here you are.

There's a known issue with this lens where the ribbon connecting to the focus assembly can wear or be pulled loose in time. It doesn't affect all of them by any means, but it's not uncommon. Symptoms can include just the type of behavior you described.