My Remote on my preamp has stopped working

You are using that preamp to control the system you have pictured in your profile? This must be a different system.

Batteries first, replace remote next…

You can point the remote at the camera on your phone and should see something flashing white light.  This will be a good indicator of whether the remote is working.

if not, new batteries and cleaning of contacts.

Good luck.

Good excuse to get a new pre! 😁

With my PS Audio BHK preamp, I will occasionally lose remote function. If I take out the batteries, and shut off and unplug the preamp, then plug it back in and turn it on, It always restores the remote functionality. Some little computer chip needs to reset, I suspect.