Brother PDuff gives us the inside skinny on this one-trick pony:

The Frigidaire dryer control board "runs home to mama" with the E68 fault code. It's the only fault code listed and the only one it knows. It indicates stuck button as Brother Reg advised. I've never found a stuck button, usually a bad board. Did have a Gallery dryer the other day with control board and interface. Threw an E68 at me so I ordered the main control board to have when going out. Turned out to be the interface. RATFARTS!!! P/N for your board is 134523200.

Part link for the Main Control Board with a one-year return policy.

Source: Frigidaire Dryer That Has Error E68 and stops every 30 Seconds