m17 R4, repair or replace?

3 y/o laptop out of warranty--has been fine but recently has done two weird things:

1] the keyboard will suddenly stop working (except for a few random keys). If I turn the computer off and let it rest (cool down?), the problem goes away. It's done this about a dozen times over the past 4 months.

2] today--the machine froze, and then SupportAssist detected "a failing component" (Hard Drive short self test unsuccessful). I turned off the machine, let it cool down 20 minutes or so, and it rebooted fine.

Question: is it worth repairing the machine or should I just scrap it and get a new one? Thanks!