01 CBR600 Speedometer not working

[sirkus]

I just recently purchased a 01 cbr600 f4i. The one problem with the bike was that the speedo wasn't working. Which I didn't really mind. But now whenever I get alone on the road or between cars, I don't want to be running 10+over the speed limit. Anyone know what might have caused it not to work? He said that it stopped working after he dropped it in his garage (he says it just fell over on the frame sliders). I was wondering if they're electronic or do they run from a cable? I'm wanting to fix this problem myself as soon as possible. I know there are some people on here that have taken these bikes completely apart and put them back together.
And I also know that I'm not the best at asking questions about tech shit, so if I may seem vague then please ask me to describe more. I really don't want to take it to Honda, but I will if I have too. Thanks for any kind of help. :goodjob: