I'm using some custom software to read 1 ADC-20 and 3 TC-08s. As you'll no doubt know, when a TC-08 channel has nothing plugged into it, it'll generally output a temperature that's roughly the room temperature that the logger is at, due to the CJC.
2 of the loggers are outputting expected values, however one of them is outputting very odd numbers. All 8 channels will spit out somewhere between 11 and 22 degrees - the room temperature is about 22. All 8 channels will have roughly the same output, but there's a lot of variation there.
Are there any known issues with using these loggers on an underpowered usb port*? That's the only thing I can think of other than the CJC or the logger itself being dead.
*I'm not going through a hub or anything, this is only a suspicion...