bluetooth peripherals not working with iMac

Hello Everyone

For some reason my trackpad and keyboard have stopped working with my iMac, I'm not sure why but they don't seem to want to pair with my iMac, the green light turns on for a split second, the keyboard light fades quickly the trackpad light simply turns off, the mouse works fine but the other two don't.

Anyone got any ideas as to how to troubleshoot this?

Have you checked the batteries?

first thing I checked

In System Preferences under Bluetooth and select advanced are the first three boxes checked?

they are

hey guys, reset the pram and everything works now, thanks for the help