1) Machine not working abnormally.

Reasons: a. power source not connecting abnormally, fuse fusing.

       　　b. air pressure not abnormally, cylinder can not work well.

       　　c. electromagnetic valve broken.

       　　d. programmable controller broken.

2) Hot-panel horn not heating, plastic can not be welded.

Reasons: a. power source of heating tube connecting abnormally.

      　　 b. heating tube burnt down.

3) Temperature of hot horn abnormal, welding result not good.

Reasons: a. thermocouple broken.

       　　b. thermostat broken.