new magic keyboard working but bluetooth says no keyboard found.

Imac 2008 2.66 GHz Intel Core 2 Duo, 4GB 800MHz DDR2 SDRAM OSXEl Capitan 10.11.3. computer checked out at genius bar 3/9/16 ok but keyboard & mouse problems so I purchased the magic mouse & keyboard which seem to be working well. after 5 weeks the computer didn't seem to be consistently responsive to mouse. went to system preferences & mouse and said battery 44% so I recharged yesterday. So far that seems to be ok now.

Decided to check battery on keyboard which is working fine but there is no display under system preferences/keyboard that includes the battery status.

I went to bluetooth & it searches & keeps saying "no keyboard found be sure battery is installed properly & its turned on" the battery is factory installed & it is working. It is on.

I charged it last night anyway on assumption maybe it was getting on the low side since purchased same time as the mouse. I checked this morning & there is still no battery status display & the blue tooth says same "no keyboard found be sure battery is installed properly & its turned on".

What might be the problem & what do I do? thank you