What’s the standard operating temperature of a Proffie V1?
This is the 2nd one in a row I’ve installed and it’s fairly warm to the touch when it’s running. I have a laser thermometer and the spot right between the big chip and the USB port is the warmest at around 115 degrees F. Is this normal?
No, that’s not normal.
Also, there is nothing between the USB port and the MCU that can get warm.
The MCU itself can get warm, but that’s usually bad.
Does that mean bad MCU or some other cause I can track down?
Most of the times, problems like these are caused by shorts. Sometimes the short is temporary, but the damage is permanent (“bad MCU”), sometimes, the short is permanent, and removing it resolves the problem completely.
So, inspect with magnification, mesure your connections and try de-soldering one wire at a time to see if the problem goes away at some point. If you de-solder all the wires and the problem persists, then there is probably nothing you can do.