It reminds me of Simasimac, which usually discusses the SE/30 model. For that model, it says its a RAM issue. Its probably not relative between these models, but it could be faulty RAM (which is obviously soldered onto this board).

However, another forum member had faulty RAM on his early model Mac, and it came up with the Sad Mac and a code that allowed him to find the faulty RAM, which happened multiple times until it was repaired. Hopefully someone else here can help.