Not sure if this helps---some of these sets had a problem---the three blinks usually means door not closed properly--remove door and look carefully at it--if it is warped from the heat---the plastic peg on the back of it will not engage the lever(it is a safety switch that prevents the set from working if the door is removed) look behind the door where the plastic peg is--if it is your problem you just have to use something not metal to move the lever and then while in place turn the set on---if it comes on normal--order a new door---they are about 5 dollars plus shipping--if you need direct help email me with the exact model number--if this has been helpful give me a vote------

[email protected]