Remote controls fail for many reasons. If no buttons at all are working on the remote, then suspect some sort of power problem. Perhaps batteries leaked, causing corrosion to the batter contacts. If this is the case, scrape the contacts until shiny metal contacts the batteries.

Another problem is that one button is stuck in the "down" position, and no other buttons can be detected until the stuck button is released. To check this, press and wiggle each button on the remote to make sure they are not stuck. Test the remote to see if it now works.

Most remote controls use extremely simple membrane keyboards. If something spills on the remote, the button switches can get dirty or gummy and stop working. We will disassemble the remote to investigate this.

The membrane keyboards on remotes are not robust. On the bottom of each button is a flat piece of plastic pained with conducting paint. Pushing a button makes the conducting paint complete a circuit, and the button fires. The conducting paint can wear out after many pushes. We will disassemble the remote to investigate this too.