It is empty.
I made the mistake of buying a T-Dozer kit which is supposedly the same board as used in the Spectra P600, but I'm not 100% sure (I do know that t-dozer had a working relationship with Spectra).
I couldn't get it to work and wasn't the only one, so I went with the OpenDTG AIO board and now can print t-shirts.
I'm willing to sell the T-dozer board for $75 for those who are interested.
FYI the T-Dozer website is no longer in service. Like Spectra, it seems the're out of business.