[SOLVED]820-2936 Intermitent VCORE


Hello guys, got an 820-2936 board here that came in December with no VCORE. I replaced some caps and the board came back to life. Last week the costumer brought the machine back again with no VCORE. I replaced U2800 as sometimes it's the culprit of that kind of problem and checked R7402. Same thing. Sometimes when I heat up U2800 area VCORE comes back for a moment and dies again. I have 12.53V on Pin 2 of R7402, 0.54V on Pin 1 and 3.3V on Pin 2 of U7400, so I have enable signal and have VIN on U7400, but still no brain/vcore. What else can I look?


I think it's solder problem on CPU. If I heat up for some seconds under the CPU area the machine boots fine. When it gets cold it stops again. Will try flux and hot air and see if it works.


Staff member
Possibly accumulated crap underneath CPU, or PCH.
Heating to 180-200 degrees for 10-15s with quality flux, can help.
Should be better to reball, if same issue persists.