Technics SA-GX500

Question

My old Technics SA-GX500 is experiencing some old age ailments. I've had the unit for a while and would love to save it if I can. The problem I'm having is this. I turn on the unit and it powers up fine. After some time (this time varies but is about 10 minutes), the power just shuts down. I try cycling the power but it won't come on right away. If I wait a day and try it again, it will power up but again, it will shut down by itself. Any ideas on what's causing this?