seleco stv 150 broken down?

hi i own a seleco stv crt front projector.it was fine untill i cleand the dust out.the next day i switched it on it was on for a few hours then just went off i turned it back on then only green and blue tube came on screen was blue with white lines through then went off again after a few seconds.i took the top off and switched back on the red lamps lit at the neck no ht.can you help