Hi there, I also have a similar problem. Months ago I did something very silly with an external power supply and blew up both IC4 amp and U3 DAC (resulting in a direct short between VDDC and GND). This caused the IC3 regulator to get very hot and the red LED to flash on powerup.
I only use this axo core board for MIDI and GPIO, so I decided to try clearing the short with carefully calculated violence now U3 and IC4 are unpowered, the IC3 regulator doesn't get hot, and the red LED doesn't flash any more. Wheee!
Unfortunately the ressurection is only partially complete. My axo core board is back from the dead, but only half-undead.
The editor reports "5V 0.25V VDD: 0.16V" in red. Attempting to make a patch live reports "Generate code complete Disconnect request."
With an external voltmeter I read +5V on appropriate testpoints, VDDA, VDD, and VDDC are all at 3.2V.
I read in this thread that there may be some initialisation code in the firmware that could help.
What should my next step be to resurrect the my not-quite-zombie axo core board?
Thoughts and ideas greatly appreciated.