So I am just looking at options here.. even with this dead port aside, we are out of ports anyway and need some expansion, and have already added the max. 2 8-EXT cards. So our only options would be to replace it completely with something else, or to pair it with a second cabinet, right?

This system is as follows;
KX-TD1232, date code 93-12, ROM P101E60905A, purchased by us about Oct. 97.
based on the ROM I'd guess it's a -1 unit. Perhaps somebody can help confirm that? how can I positively identify what dash I have?

question: can a -1 be paired with a newer unit, ie a -7, and if so could the -7 be the master and would you gain the additional features of the higher rev unit on some or all ext's?

looking at this;
https://www.ablecomm.com/panphonsysve.html
the words "Increased processing speed, circuit board modifications" under the description for dash 2 concern me that there might be problems with compatibility between pre and post -2 units?

Thanks