MH-721 cutter head problem

[lungrendrop 0]

Newbie here, Got a second hand MH-721 last week and works pretty good but found out that the head drops 7 inchs worth in the middle of the machine. Its like the z-axis looses connection when it enters the center of the machine. How I found out is when the machine is on it lifts the cutter up and if you push it from right to left about 10 inchs into the machine the head just drops like you turned the machine off the z-axis, but at about 17 inchs the head powers up and lifts again. Any ideas on why this is and how to fix it? I have not broken into the machine yet.

Thanks

Lungren.

[Dakotagrafx 7,297]

that is a new one - thinking maybe bad cable to head - breaking connection at that point . . . ? ? ? ?