Q: Myspacebar

try another keyboard, if the micro switch under the space button is broken then you would need a new one

As suggested, to try another known good keyboard, even a windows PC version

at least would be a means of troubleshooting to see if this symptom goes away...

• Keyboard mappings using PC keyboard on a Macintosh:

https://support.microsoft.com/en-us/kb/970299

Beyond testing, if you choose to use a functional PC keyboard in the absence of

a working Apple mac keyboard, this article shows comparison keys between the

two kinds of keyboards; intended for users of BootCamp, to show how to use an

Apple Keyboard in Windows, the article shows the keyboard equivalents...

Use your Apple Keyboard in Windows with Boot Camp - Apple Support

{Or you could make an art-form out of making 'word totems' by using Return-Key

to hard break after each word. Although uncommon, it may become a new fad;

and should work across nearly any device.}

Not sure if a reset of the SMC or system management controller, power management

unit, would help; if the problem were proven to not be the keyboard after all. To have

and keep proven good spare USB keyboards on hand is a good idea, to troubleshoot.

Good luck & happy computing!

time to get shopping then.

Yes, sounds unyielding especially without a second known good keyboard

to troubleshoot the issue. Is the Keyboard Viewer activated so you can use

a mouse to pick around on the tiny keyboard in there? That would allow you

to also check the system is OK, & further narrow the issue to failed keyboard.

• Apple OS X 10.8 Mountain Lion - Using the on-screen keyboard (viewer)...

https://mcmw.abilitynet.org.uk/apple-os-x-10-8-mountain-lion-using-the-on-screen -keyboard/

Hopefully the problem is only a keyboard & not a gremlin had moved inside.

One would think you must know someone with a computer with a working keyboard you could try. Tell them, "I'll give it right back."