While I don't have much insight to share, and my own CoDi is working (though it's buggy), I think it could be helpful for others, if you would post some pictures from the replacement process, perhaps in a separate thread, with a descriptive name, like "How to replace the CoDi [pictures]", to make it easier for anyone interested to find it.
For what it's worth, I do experience random reboots, but fairly seldom, maybe once a month or so, but I haven't thought much about whether they are related to my CoDi. Up until CoDi FW 1.1.1.14, my CoDi used to crash maybe five times a day. On 1.1.1.15 it went down to maybe three and on 1.1.1.16 it usually works for several days between crashes. When it does crash, it usually gets stuck showing either the Planet logo or nothing. Most of the times, I can just disable and re-enable the CoDi in the notifications shade, but once in a while, it just won't restart properly.
Those times, instead of waking up and showing the clock, it shows the "HELLO, I AM COSMO!" animation, as when the device is starting up, but then goes black again... Um, it just did that, right now... what a coincidence(?) Come to think about it, once that happens, the whole device has a tendency to, shortly thereafter, either reboot or hang... which it did right now... so, well, maybe there is a connection... um.
Anyway, I was going ask, if you have tried leaving the ribbon cable connected and just turned your CoDi off in the settings? If you did, would your device still randomly reboot? If it did, is it still doing that, after you disconnected the ribbon cable? It is my understanding that some people here, aren't using their CoDi at all, and if physically disconnecting it could improve overall system stability, I suppose some of them might want to know about it.