Secondary Error code 0031, power rail issue.

Hello iFixit!

I recently picked up a broken xbox 360 for $5. I wasn't expecting much, but it was actually working when I got it! It would overheat the eDRAM, in about 10 minutes. Replaced the paste, and it didn't help. I checked the V_GPUCORE Power rail, and it's fine. But after about 3 weeks of sitting, it now will turn on and flash 3 red lights. Using sync and eject, it has error 0031. Reading online, the common issue is a bad power regulator. They have information on xenon library, but it's very vague on where to check this stuff. So, does anyone know, where i can check if V_5P0 or V_MEM are shorted? And, is there a refrence image i could use to try and find a bad regulator (if thats the issue), and one that has a map of the power rails? Thanks for any help :)