Re: head help
A Jabsco 37010 is an electric toilet which has some kind of "chopper" between it and the tank. This could be what the OP is calling his macerator, or it could actually be the macerator. Possibly it's located between the toilet and tank on an electric head.
A vacuum flush or manual pump toilet will have the macerator only on the dump tube, like Fireman431 said.
You can go to the ITT (owns Jabsco) help page and look at their 37010 problem diagnosis pages:
http://www.ittflowcontrol.com/support/37010-toilet-diagnosis/
The answer for the problem the OP described is:
Fluid/effluent is not being pumped out of the toilet
This can be caused by a blocked, obstructed or failed joker valve - clear the obstruction or replace the joker valve.
There may be a blockage round the chopper blade - clear the obstruction.
The centrifugal impeller may be damaged - check all the blades are intact and the set screw is tight
I have no idea what a "joker valve" is, or where your chopper blades and impellor are located. You should be able to go to the ITT (Jabsco) website and download the manuals for your system.