There are several possible reasons why your monitor isn't displaying information so it's very important that you step through an ordered process like the one I've outlined here.
E nwere ọtụtụ ihe mere ihe nyocha gị anaghị egosiputa ozi, ya mere, ọ dị ezigbo mkpa na ị gafere usoro iwu dịka nke akọwapụtara ebe a.