NAD 502 stops playing

I found a guy selling this unit. Any idea what might be wrong and how much it would cost to repair?
Someone wants to sell a defect NAD 502? This is a model that entered the market in the early 90ies, do you know how old the unit on offer is? Bear in mind that units in good working conditions changed hands a few years ago for less than 100$.
I was thinking it would be an inexpensive upgrade to my HK 5 disk carousel. I didn't mind if i had to monkey around with it a bit, but i didn't want to end up having to spend much on it. $30 is the price as broken.
I'd steer clear. I bought this unit new when it came out; the display stopped working after a month, then lasted a month again after it was repaired, and then after just two years it started skipping badly on unscratched CDs. Then I got rid of it. I've had nothing but good luck with NAD's amps, but that particular CD player was another story.

Good luck on the hunt. If the budget is important, you'd be better off spending that same $30 on a Playstation One, which is what I've done.