When I boot the system I hear the CPU processing start then suddenly stop. The solo light is on the entire time, frozen for about 3 minutes while my monitor is black and not receiving any signal from the CPU. Then I get error 43 host did not boot message.
Great! That's the kind of info and problem description I'm looking for and gives us somewhere to start.
The (Computer-)Display needs to work in order for us to be able to see what's going on, and to make the necessary settings.
Did this D8B computer work with this monitor before?
Do you have another Monitor, or Monitor cable to try?
If you did all that and the display still doesn't come on, I'd suggest to disconnect the D8B rack unit from the power outlet, open the rack case, and re-seat the cards in it.
Basically, either your monitor, monitor cable or your video card in the computer aren't working right, since there should ALWAYS be something showing on the monitor, even if there was no harddrive or operating system installed on the rack computer at all. Sometimes, re-seating makes them work again... sometimes a card can also go bad.
(It could of course be worse and the mainboard could have gone bad, but let's try another monitor, and if that doesn't work, re-seating the cards in the rack-unit, first.
Also, btw. - the monitor should show something, even if the console isn't connected at all. So, that's why we're starting to look for the problem at the rack unit.
Let's try this first, and then describe what you see. Best of luck, bringing the monitor back!