You can check any type of Sky remote control is working,  using your mobile phone. To do this get your phone and put it on video mode. Then point your remote at the camera of your phone and press any key on the remote e.g Sky button. You should see a blue light flash from the front of the front of the remote on your phone display. See arrow on photo. This is the Sky remote infra red transmitter and is not visible to the human eye directly. If this flashes then your remote is probably  o.k. You can check each button on the remote by doing this.

This article has been useful and Id like to recieve more information from Digi Repairs UK regarding all things Sky.