F110 V1 problem

My F113 v1 developed similar issues years ago. I am afraid that your sub is in need of repair.
Is your sub under warranty? If so give JL Audio a call. They have excellent customer service.
If not under warranty, and feel comfortable doing not too complicated electrical work you could do a search online for JL Audio subwoofer repair. Several folks have posted very detailed step-by-step online (basically just replacing a couple of capacitors that tend to go bad).
If you end up deciding to send the unit to JL Audio they can give you instructions on how to remove the innards of the sub and ship it to their offices. That will save you from having to ship the whole sub back to them.

I finally sent the subwoofer in for the $450 flat fee non-warranty repair at the beginning of the year and all is good. As I mentioned in my first post I have two of them and like clockwork, the 2nd one now has the same problem. I sent it in and am looking to get it back in 10-15 working days. These things must have timers on them for triggering the failure.