Cash Drawer Will Not Open

[stagenine]

We just set up to Square POS kits that came with the following hardware:

Square Stand

iPad Air 2

Star TSP100 Thermal Receipt Printer

Printer-driven Cash Drawer

Contactless reader

One POS kit is working as expected, however, on the other, the cash drawer will not open.   To try to isolate the issue, we've swapped the hardware around and found that everything appears to be working. i.e. when I moved the cashdrawer to the working set up, it opens fine.  Same with swapping the printers. It appears at this time that the problem can be isolated to the specific stand/iPad. 

Not sure how to troubleshoot this at this point.  The iPads and other devices are set up identically as far as I can tell. 

[stagenine]

Solved.  In a bit of a facepalm moment, we realized that it matters which end of the RJ-12 cable plugs in to the cash drawer as the pinout is different on each end of the cable.

[IceCreamStan]

Me too.  So used to unhelpful things being stuck to cables I ignored the very clear instructions on which end goes where (landed here from google)

[DesignsByJessey]

i am having the same problem. I have a Star TSP100 Thermal Receipt Printer Printer-driven Cash Drawer and ive swapped ends and still not opening i even bought a new RJ12 cable and sane thing my ipad is a 5gen