The first thing I would do is check for 240 VAC to dryer. The heating element needs 240 VAC while the motor needs just 120 VAC. Make sure both breakers are On.
You have to have a multimeter. I'm not sure about your tester, I never used a such.
If there is nothing wrong with the voltage, then you have to check for continuity the heating element, the high limit thermostat and the cycling thermostat.
This is definitely not the thermal fuse, because the dryer would not do anything if this fuse is blown.