HELP! My Juki foot lift air power slowly faded away and quit on me

[TuffPossumGear]

Rocking a Juki 2212n-7 (basically a 2210-n7, but with a 2nd stitch length knob to switch between) with a SC510 control box.

Yesterday, my automatic foot lift started to lag a bit and slowly wavered in and out for about 45 minutes of trying to get it to work, before quitting altogether.
I know I have air power since my backtack and pneumatic reverse button work and they are button/air actuated, but I have no power to the foot lift function.

I have no clue where to even start and really would like to not pay for a technician visit from a couple hours away.

Do you have any advice??

Much obliged,
Jayberry

[Misadventure Gear]

My first thought was a leak in your air hose. If you've eliminated that possibility, I'd look at your solenoid for the foot lift. Perhaps you can function test it with a volt meter.