It is recognised on bootup as I can enter safe mode (with the shift key), but I still cannot log on. I have reset SMC (by disconnecting the power) and NVRAM (Using Cmd Opt P + R) successfully. Any ideas welcome
iMac 21.5", macOS 10.15
Try connecting the keyboard to your Mac with it's charging cable and see if it will work as a USB keyboard. Then go about resetting the NVRAM and SMC:
Reset NVRAM or PRAM on your Mac - Apple Support
How to reset the SMC of your Mac - Apple Support
When done see if the keyboard can be recognized without the charging cable.
For anyone interested or with the same issue I have resolved this. It appears the identifier used for the Bluetooth handshake had become corrupted. Powering up with the keyboard turned off resulted in the "No keyboard found" message, which had not been there before. It then auomatically tried to connect, and succeeded on the second attempt.
Try a wired Keyboard or a Safe Boot...
Safe Boot from the HD, (holding Shift key down at startup), does the problem occur in Safe Mode?
If you read the text with my query you will see that I have already done that. It enters safe mode (so does recognise the keyboard) but will still not type in a password to log on.
Have tried with it connected, Have also reset SMC and NVRAM as described in my original message. Still no joy.
Thanks for the report.
The rechargable bluetooth keyboard on my iMac is not recognised when trying to enter logon psssword.
