So I finally got around to installing the CIVA INS into the 727... Took a lot of trial and error in the panel.cfg but I finally got it to power up  . The only problem is when I turn the INS's to STBY mode to input my initial position. I can input my latitude and insert it just fine, but when I try to input my longitude, it will not allow me to enter my longitude (When I press the 4 key to input my longitude west, nothing happens). What can I do???