Mamiya M645J not fire

[EduAQA]

I just bought a M645J on ebay, but now seems that comes defective, although is in a very very good looks. What happens in is:
A followed the Manual, setting to MULTI position, move the rotate the knob until it stop, but when press the shutter nothing happens, it goes to the end so light like a broke and nothing happens. Can anyone give some help. I didn't buy the lens and finder yet. and not sure if it should fire without them.
Thanks.

 

[Jaf-Photo]

Check the battery by pressing the battery check buttom, which should light the BC light by the shutter speed knob. The shutter won't release without power. You should always use a 6V Energize 544 silver oxide battery.