Actually, I have a busted 1084 with a good power switch. Which 1084 do you have? If it's the one that was made by Philips/Magnavox, I have the power switch, with the big square button. :-)
Let me know, I'll just rip it out and send it to you, no need for payment.
-Mike
Does it look like the first monitor picture on the top of this page?
http://www.amiga-hardware.com/1084.html