Here are the steps I would take to check your dryer.
I know you have done some of these already.
1. Check for 240 volts were the dryer cord attaches to the dryer.
Some times people will check power at the outlet and it's ok, but later find out it was a burnt up connection were the power cord attaches to the dryer that was giving them the problem.
2. Check to see if you have 240 Volts to the heating element.
Put one probe on each terminal of the element to check. If you have power to the heating element, but it does not heat then replace the element.
3. If you don't have power to the heating element then I would check the thermo cut-off that is mounted up high on the left side of the heater canister.
Check the thermo cut-off with a ohm meter. If it ohms out it's good. If you get no ohm reading just as if you did not have the probes on the thermo cut-off then replace the thermo cut-off.
Make sure you have the power off and at least one wire pulled of the thermo cut-off when checking it with a ohm meter.
4. If the upper thermo cut-off is fine I would then check the second thermo cut-off that is located near the bottom of the heater on the left side.
If all the above items seem to check out ok then I would move on to checking the timer and the switch on the motor.
Sometimes you can check the timer just by looking at the back of it. There maybe a burnt wire or spade on the back of the timer.
The switch on the motor is a centrifugal switch and it kills the power to the heating element when the motor is not running and kicks in power to the heating element when the motor is running.
This way the heater will not operate if the motor blower is not running. It's a safety thing. If the contact are burnt up on that motor switch it maybe the reason why you have no power to the heating element.