Flew LAX - AMS several times this year with KLM. Each time, checked in at NW WBC counter and then luggage has to be taken to Xray machine. My luggage had combination lock on...(standard travel type). Told the guy loading luggage into machine that lock was "open", i.e set at open combination so if necessary TSA had access to luggage. Asked if TSA people would give the tumblers a spin before loading onto luggage belt. He annotated luggage label and told me to walk down to the left/front area of the machine where there is a waiting area. I saw luggage cleared through machine and simply asked the guy receiving it to spin the tumblers to close the lock... no problems at all.

Hope this helps.
Exraf