Here is the parts breakdown
Replacement parts for General Electric DRSR483ED2WW Electric dryer | AppliancePartsPros.com

As with most GE's I could not find any tech info.
If you do not have a wiring diagram, check inside the unit's control console they often put it in there.

Following is a good source for basic dryer repair info. There are some example wiring diagrams for GE's
http://www.applianceaid.com/dryers.html

Yes the no heat problem can be related to no timer advance.
Try running the unit in timed dry mode.
If the timer now advances then you probably have a burned out (open) heater coil.

The way this works is that in timed dry the timer motor gets power directly from the line.
In auto modes it gets power through the heater coil when the heater is shut off. Often there is a resistor in line with the timer motor which reduces the voltage from 240 volts to 120 volts to run the timer motor.
I believe this applies to your unit, see Item 80 in Section 1 of the parts.

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. Be careful 240 volts is lethal.
If OK
Unplug the unit and check the heating coil for continuity
Thermostats and thermal fuse all should be 0 ohms.

Be sure to disconnect one side of and device you are measuring this prevents reading an alternate/parallel circuit path. Also use your most sensitive ohms scale.
There is a good Sticky at the beginning of this forum on meter usage.