Is error 99 on a Canon 5d fixable?

I'm a Nikon shooter myself but I found a cannon 5D on a website for $100.
user says it has error 99 and I was wondering if this is fixable and could I fix it? And make a quick buck off it Or use it

Error 99 is a catch-all error code. If you know programming, that's the "else" part after everything else has been defined. Unless you know exactly what caused it, you won't be able to fix it.

That's a 5D. It's an expensive camera. Chances are, the owner has already exhausted all means to have it fixed. Even at Canon itself perhaps. I'm almost sure it's a goner.

Try these things, see link

DON'T BUY TROUBLE!

You don't think the owner tried everything to salvage that expensive camera long before deciding to dump it on someone else's lap? Unless you're just interested in buying a paperweight.

He wisely tells you it has a problem; so you can't come back and say you didn't know, and if you go "legal" on him, he'll defend himself by saying he warned you BEFORE you decided to buy it "as is," and you'll lose money and will have wasted your time.

You should not touch it with a 10 foot pole, … Much less a $100 bill.