Monitor Chassis only has 4 signal inputs ?

[claypool]

I recently had two cabinets while swaping one tube and chassis complete into the new cabinet , the jamma wiring harness is not the same now I dont understand two things.  the monitor and tube I have are really old and the chassis only has 4 signal inputs on the plug from the jamma harness to the chassis,  it seems to be missing the ground is this needed for it to work?

Second thing which seems odd is the AC input on the chassis  has a ground wire as well as Active and Neutral. Shouldnt the chassis be isolated from earth via the transformer?

Thanks

[SirPeale]

And without pictures, make/model, or any kind of USEFUL information, this will remain shrouded in mystery.

[claypool]

Here is a picture of the no name monitor chassis , the tube is a hitachi 19-20 inch monitor