As another writer notes, a failing disk will certainly cause delays - when you attempt to read or write on a bad disk block, the system attempts to recover; when there are many bad disks, this takes a long time, first to locate a usable disk block, then to create the links to point to the new usable block, then to rewrite any recoverable information to this location. If there are many such instances, this becomes progressively more difficult and time consuming until complete failure occurs. Usually you get a warning; this MAY be yours.
There are, however, other possibilities. Sometimes the default display mode - screen size and resolution - are either not optimal or don't work. Some boot modes allow a "failsafe" option that will find and utilize lower display resolutions that are common to almost all video and display hardware, and this will also provide a workaround.
The long delay suggests some kind of "contention"; whether your system is seeking to read disk blocks that are failing, video or display components that are not functioning properly, or even both scenarios, the issue or issues you are encountering are greatly increasing start times. Check into both of these possibilities, beginning with the bad disk blocks. Most boot loaders can also check boot disk integrity; see if your loader has this option; it should.