dryer won't heat

I have test all the fuses, all test good. Change the timer and still no heat.

Have you checked the heating element? If that is broken, it will need to be replaced.

A model number would be useful.
http://www.appliancepartspros.com/modelnumber_locator.aspx

Start by checking the power.
The heating element requires the full 240 volts.

Try flipping the breaker off/on slowly a couple times. Sometimes you can loose half the line without actually tripping the breaker.
Check the voltage at the wall receptacle
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 terminal strip in the machine to make sure none are loose or burned out
If OK
Check the power at the terminal strip.
Do this with the heater off and on.
Be careful as 240 volts is lethal !!!