820-3787 Powers On No post


Hello. Got this board here and it was not turning on, shorted PPBUS_G3H line, which I traced to bad U7330, which I replaced. Board worked perfectly yesterday after the replacement of that chip, I turned off the machine and left it sitting on the bench to finish assembling today. Today, when I arrived at my workshop the machine was turning on but giving no POST. After some inspection I detected CPU VCORE was not present and I have now a full short on L7330/20/10. I thought maybe U7330 was bad again and removed it, short persisted. So I removed R7330/20/10 to see on what side the short is, and for my bad luck, it's on CPU side. Tried injecting voltage, it sucks 5A from my bench PSU(maximum it can provide) but nothing gets even a little warm to touch. Any ideas?


Staff member
Your PSU is in protection mode, doesn't inject voltage at all.
Just check with your voltmeter.

CPU is dead for sure.
I hope you removed the heatsink for test.


Yes, heatsink removed of course... As I thought, dead CPU, just wanted a second opinion on that. Strange thing is it died after being fixed LOL. Strange.