Paladin, Before something bad happens, I strongly recommend that you replace all the electrolytic capacitors in your Phase Linear/Pioneer turntable. After all this time, and after being stored unused in your garage, especially, odds are that at least some of those capacitors have gone leaky (electrically speaking if not also fluid-wise), and this can lead to damage to transistors and ICs in the circuit. Some of those ICs will be hard to find if needed.
If you can find a service manual on the internet, it will likely have a parts list, which will include all capacitors and capacitor values. You can then use that list to order replacement electrolytics from an on-line company like Digikey or Mouser or Newark. The total cost of such a purchase is not likely to exceed $20 to $30. If you can solder, you can do the rest yourself.