Trinity board shuts off after RDoD

I’m trying to fix this trinity that came in yesterday. It wasn’t turning on at all, only beeping. While probing I wasn’t getting any 1.8v, so I replaced the voltage regulator and it finally turned on. Problem is that RDoD shows up in less than 5 seconds, and then the console shuts off, and I can’t retrieve the secondary code error. The southbridge seems fine, and so is the power brick. I have all the standby voltages. What else could be the problem?

Thanks!