Blade will not go up or down.

[teddyu 2]

I just got a stand for my MH 721 put it together and sat the cutter on it and the blade will not go up or down now. Can anyone help?

[MZ SKEETER 4,708]

Did you use a ground wire and ground the cutter to the stand?  You should, as the static from the vinyl will go thru the carriage head and fry the z chip.   Can you manually lift the blade holder up and down? 

[teddyu 2]

No I did not ground it and yes you can move the holder up and down. 

[MZ SKEETER 4,708]

from another forum member posting,  This has has been posted many times   " guess is a z-chip on the mainboard if it had been working fine before.  you can take the cover off the carriage and try touching a 9v battery to the wires to see if it reacts - if it does then change the z-chip - if it doesn't then carriage"