Quote Originally Posted by spaceorange12 View Post
Any thoughts on what wiring problems might prevent a power supply from turning on?
A short between 12v and ground will keep the power supply from turning on. When it detects the over-current, the power supply will protect itself by shutting down the output. Well, at least most of these switching power supplies will.

What electronics suite do you have (RAMPS vs RUMBA vs. ?)? Remove all the 12V connections to the electronics, and then reconnect them one at a time. In otherwords, connect power for the electronics iitself first. If that works, then connect motor power if that is separate for your electronics. Then try connecting heater power, etc.