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Replacement parts for DDC0580BAL models | AppliancePartsPros.com

Getting tech info on GE's is near impossible. They like to keep things a secret.
Hopefully the following will be of some use as much of it is guessing on my part.
A wiring diagram would be helpful to you. Take a look in the control console often they store one in there.

First I would check the power to the unit.
First try flipping the breaker off/on slowly a couple times. Sometimes you can loose half the line without actually tripping the breaker and the heating coil requires the full 240 volts.
If this does nothing.
Measure the voltage at the plug
L1 to L2 should be 240 volts
L1 to Neutral and L2 to Neutral, both should be 120 volts.
If OK
Unplug the unit and check the wires at the unit's terminal strip to ensure they are properly connected and none of them have burned off
If OK
Plug the unit in and check the voltage at the terminal strip. This is just in case you have a bad line cord.
[COLOR="Red"]Be careful 240 volts is lethal.[/COLOR]

If OK
Unplug the unit and check the thermostats for continuity.
I see 3 of them in the unit.
One on the heater (Item 507 in Section 4) and two on the blower/filter area (Items 315 and 316 in Section 3)
When you checked them did you disconnect at least one side of them. This prevents you from reading an alternate/parallel circuit path.
I cannot tell which is which but usually the one on the heater is the hi-limt.
So I assume the other two are the cycling (control) thermostat and the thermal fuse.

Sorry I could not be of more use but with a little luck someone else will jump in with more suggestions.