How do I Run Commodore 128 in 64 mode?

Well i know how its just when i try the 3 steps i know to get in in 64 mode i get issues...

1. I will load the commodore while holding the Commodore key and the screen will stay black.

2. I will put either my Epyx Fast load cartridge OR my mach5 cartridge in and boot and i get a black screen when i turn on the commodore.

3. I will type "go64" at the ready thing and it will say "ARE YOU SURE?" I hit Y and return and it will then do nothing

Whats going on here? What can i do to fix this? I want to play some of my games but most (if not all) require the 128 in 64 mode.

A C64 cart inserted before you turn it on will start the 128 into C64 mode.

If the screen is blank have you checked to see what video input your monitor is set to? I have a 128 connected to a 1084 monitor so I can do 80 column mode as well as 40 column mode used for c64 emulation. The 2 video modes need 2 different cables and I have to flip a switch on the monitor going from one to the other.

Yes indeed. Is the C128 boot screen all black with 80 column text, or does it have a light green border and 40 column text?

I think its black with text at the top for Basic V 7.0 or something like that.

It sounds like there is something wrong with the computer.

My C128 goes straight into the back of my 1702 monitor using the standard AV cables, and it boots right into C64 mode with any of the 3 mentioned commands/methods...