That's very odd, that new board should of fixed it.
You are absolutely sure the dryer is getting 240 volts?
First, you should have a dual breaker in your home breaker box, find the one that says DRYER, then turn them both OFF, then ON again and see if that fixes it.
If not, I've run into many dryers that will RUN and NOT HEAT or NOT RUN AT ALL on my service calls. You may have a broken wire from one of the hot legs that connects to the terminal block in the back of the dryer.
Unplug your dryer, and pull it out from the wall and remove the metal cover where your power cord connects to your dryer and see if any of the wires have burned.
You would need to check for 220-240 volts at the terminal block with a multimeter
Put your multimeter leads on both ends of the terminal block, it should read 240 volts.
Remember Black & Red on the ends are HOT, White in the middle is NEUTRAL
Then put one of your meter leads in the middle of your terminal block and one on the end you should read 120 volts, then on the other end you should read 120 volts as well.
Look at this from another member that had this same issue:
(click to enlarge)