Q: external isight gets very hot and doesn´t work

Keep iSight unplugged unless you get it repaired: http://www.ralphjohns.co.uk/EZJim/EZJimpage11.html

(The link about iSight feels warm is unavailable. Apple no longer allows access to it.)

If you cannot find any other source for the part(s) you seek, your Apple Authorized Service Provider may be able to give you some ideas.  Because some parts may be proprietary, it is conceivable that your the choice for repairing your old external iSight may be to contact Apple directly:  http://www.apple.com/support/isight/service/

Alternatively, you may wish to consider replacing your iSight with a Mac-compatible camera.  Several of the many available choices are shown in http://www.mac-compatible-web-cam.com

Message was edited by: EZ Jim

Mac OSX 10.8.3