Controller is getting hot

Hey guys! Long time to talk, after 2 years I am back to working on the K40. Life happened and I am excited to get back to it.

I went through Don’s schematic and have it hooked up but my OEM controller is getting hot on one of the ICs. The original design used a massive resistor on the L- to tube, but I didn’t add this as per Don’s schematic. I don’t think this would cause anything as it should be separate.

What do you think it could be? How can I use a DMM to track down the issue?

More info please. Moshi or Nano controller?
The ballast resistor is used only on the Moshi controller.
Also if you can describe the chip or find a number on it.