tcampbell34
Member
This board had some minor corrosion on the back side of the board near the LCD connector, but the LCD connector itself is clean. Original issue was a short on PPBUS, which I cleared by replacing C7395. Then when I tried to turn it on, it was taking 20v 1.8amp without the battery and was not posting. PCH and UA600 were getting warm on thermal cam. I was getting about 1v on CPU_Vcore and .9v on GPU_VCORE rails at this time. I then decided to replace UA600 and after that, I was no longer getting any voltage on GPU_VCORE, but the board was fluctuating between 400-600ma. Now CPU_VCORE was 0.65v and I confirmed the board had USB activity now, but no video due to no GPU voltages. I realized that I did not solder UA600 very well so I replaced it again and then I was back to the same issue I had before. Board was taking 20v 1.8amp and not posting but I had 1v on CPU vcore and 0.9v on GPU vcore. Seems like something with the GPU is blocking the CPU from posting. PCH still gets a little warm, but not too hot so it might be normal. I decided to UC the board incase of some crap under a BGA chip, but now I have lost CPU vcore voltages. Now I am stuck with the board at 20v and about 370ma. What seems odd to me is I have PLT_RST_L at 3.3v but have 0v on PPVCC_S0_CPU. Here are some more voltages:
ALL_SYS_PWRGD - 3.22
SMC_DELAYED_PWRGD - 3.41
PM_PCH_SYS_PWROK - 3.31
LPC_PWRDWN_L - 3.32
PLT_RST_L - 3.32
PLT_RST_L_BUF - 3.319
CPU_VCCST_PWRGD - 0.988
CPU_VR_EN_R - 3.23
PPVCC_S0_CPU - 0
PM_DSW_PWRGD - 3.41
PM_PCH_PWROK - 3.32
L7030 - 12.66
L8000 - 1.023
L7960 - 0.964
L8020 - 1.801
L7900 - 1.2
L7600 - 5.15
L7660 - 3.329
L8410 - 0
L7410 - 0
L7420 - 0
L7211 - 0
L7221 - 0
L7231 - 0
L7330 - 1.051
LA640 - 0
LA650 - 0
LA350 - 0
LA300 - 145ma
LB700 - 0
L3500 - 0
ALL_SYS_PWRGD - 3.22
SMC_DELAYED_PWRGD - 3.41
PM_PCH_SYS_PWROK - 3.31
LPC_PWRDWN_L - 3.32
PLT_RST_L - 3.32
PLT_RST_L_BUF - 3.319
CPU_VCCST_PWRGD - 0.988
CPU_VR_EN_R - 3.23
PPVCC_S0_CPU - 0
PM_DSW_PWRGD - 3.41
PM_PCH_PWROK - 3.32
L7030 - 12.66
L8000 - 1.023
L7960 - 0.964
L8020 - 1.801
L7900 - 1.2
L7600 - 5.15
L7660 - 3.329
L8410 - 0
L7410 - 0
L7420 - 0
L7211 - 0
L7221 - 0
L7231 - 0
L7330 - 1.051
LA640 - 0
LA650 - 0
LA350 - 0
LA300 - 145ma
LB700 - 0
L3500 - 0