Astro Saber only works out of housing

I just bought an Astro Saber II that was reported to have no internal audio. Powered it on, verified that it passed POST, and yeah, no audio. Being one to always check first if everything is plugged in, I pulled the chassis and lo and behold, the speaker/mic flex was loose. Plugged it in snug, tested it with a Jedi battery held to the pins on the back of the chassis (it really IS just an XTS3000 in a different case!), everyone is happy. I also replaced the display board with one from another Astro Saber, as the one it came with was losing pixels.



Put the chassis back in its housing, snug the nuts, pop a Saber battery on, and...nothing. Try a different battery (different brand): nothing. Pull the chassis again, test it with Jedi battery: works perfectly. Plugged the old display board back in, tested with Jedi battery: works perfectly.



Now I'm stumped. When I opened the radio the first time, I didn't do anything to the housing. Didn't spray any cleaner in it, poke at it, nothing. Just set it down on my workbench. Is it possible that seeing voltage on the XTS battery pins caused the controller to think it's in an XTS housing and ignore the Saber housing flex circuit? I don't see why that would be, but I find it equally unlikely that the Saber housing flex gave up the ghost the moment I de-mated it from the chassis, with no visible damage, corrosion, or any sign of dust PR moisture intrusion.



What gives?