i have 14 chilis and 10 of them have been running for weeks and weeks without problems. the other 4 are new. 1 of the new ones runs fine for about 1-2 minutes then starts showing an error messages then it goes sick. in the midst of starting and stopping bfgminer a million times while trying to get that one working 1 of the 10 that had been running fine stopped working and now it never shows up in bfgminer even after power cycling it and switching usb ports and switching power supplies.
What do the LED lights on the chili that has the issue look like.
Remember when you power cycle, etc.. you should wait until all of the LED lights on the chili stop blinking before starting the mining software. This can cause it to hang and not be found.
What error messages are you seeing with your other chili? Have you tried switching it to a different USB port/running it solo to see if it continues with those same issues?
Hopefully we can help you out!