I'm probably not reading the first sentence proper, not really understanding it.
So, after your computer came back from a (computer) shop. What ever problem it had was fixed, then sat around your house for a year, suddenly it couldn't play games, and didn't have any Audio. Is that correct?
Anyways, what you could do, assuming you have not tried, is get an Audio Card, and see if that fixes the issue.
My question is: When you say it doesn't play any games now, are the problems all Audio-related to begin with, or is the audio problem just one example?

