I recently purchased a barely used Jet AFS-1000B air filter for my shop which I'm very happy with. The only issue was the remote had 2 buttons that did not work (On/Off, Speed). The third button (Time) still worked.
I didn't know if others have had an issue with their remote not working. In the event others have had issues I thought I'd write up how I repaired mine. The electronics of this remote is likely typical across air filter remotes so it may be useful for other brands as well.
The short version of my remote issue was it had 2 tactile buttons that had failed (6mm x 6mm x 5mm). However, this info could likely help get most any issue with a remote working. There are only a few components and the main IC chip datasheet on the board gives a list of typical components which should allow you to cheaply repair any issue with a remote based on this chip. This all assumes you've got a soldering iron and some basic soldering ability.
This is my JET AFS-1000B air filter with partially working remote (time button only).
01_JET AFS-1000B Remote.jpg
Using a camera without a filter (front camera on an iphone) you can see if the LED of a remote is functioning when you press the button. In my case 2 buttons showed no LED and one button did illuminate the LED.
02_LED_No_Light.jpg
This is the board removed from the remote. The IC chip on the board is a Ceramate CP8223R IC for remote emitter with built-in ON/Off, Speed, Time, RHY/SLP and Osc; 5 keys. The data sheet is easily found online and very helpful.
I checked continuity of the buttons and sure enough the On/Off and Speed buttons did not show continuity when pressed while the Time button did show continuity.
03_Board_Frt_Back.jpg
I purchased the 6x6x5 mm tact buttons from Amazon to replace the 2 non-functioning buttons
04_New_Tactile_Buttons_to_Board.jpg
This is an application schematic from the datasheet which is how it was implemented on the board.
I've also included my really bad sketch showing the button orientations on the board.
05_Bad_Sketch.jpg
Success! The remote now works!!
06_Functioning_Remote.jpg
Below is a list of board components that would likely fix any issue with the remote.
07_Board_BOM.jpg
So if you have a non-functioning air filter remote you may be able to revive it for minimal cost.