[sps2112]

I have quite an interesting problem. Our dryer will often become unresponsive on the keypad control panel . If you hit a button to start the cycle, 40 Minutes will flash and the check lintscreen light will blink. The cycle will start but it beeps in what to me sounds like some sort of code, and then it will stop running. I have cleaned everything in the duct system and underneath with compressed air and the shopvac. Sometimes it runs fine for weeks, and sometimes I'm ready to chuck the whole thing in the trash. Is there a more in-depth repair manual or has anyone ever heard of a problem like this?? Thanks alot