unable to connect to keyboard. System does not detect keyboard even after switching on and off. Mouse working fine. Earlier was working fine. Keyboard is not detectable by I mac . Tried a different keyboard same problem.

Hey Gautam5058,

Thanks for the question, and welcome to Apple Support Communities.

The following articles provide troubleshooting steps that may help to resolve your issue:

Apple Wireless Keyboard: Difficulty during pairing process

http://support.apple.com/kb/TS1569

Bluetooth Quick Assist

http://support.apple.com/kb/HT1153

You may also want to try resetting your computer's PRAM and NVRAM.

To resolve this issue:

1. Turn the Apple Wireless Keyboard off.

- For an aluminum Apple Wireless Keyboard, hold the keyboard's power button for more than 3 seconds.

- For a white Apple Wireless Keyboard, turn over the keyboard, and turn the power switch to the off position.

2. Click the "Continue" button as the Setup Assistant instructs.

3. Power the Apple Wireless Keyboard back on.

4. Enter the 8-digit passkey and press Return. Important: You MUST press Return after you enter the 8 digit code.

Thanks,

Matt M.

Try resetting the PRAM and SMC.

Barry