Cycling 820-3437

[bjf]

I have a cycling 820-3437. It's a little different than a normal cycling board though. The clock chip is going up and down along with the SMC clock chip. G3H voltages are there. 3V SUS is present. SMC_LID and SMC_RESET_L are there. When it cycles, everything comes up that I can think to check. I've replaced U1900. No change. Board was liquid-damaged most likely but it was cleaned before it got to me and nothing looks visibly burnt besides the U5110 area which I cleaned up. Any ideas what would cause this?

 

[2informaticos]

Check/resolder/change U1950.
If ALL_SYS_PWRGD pulses, check if VCORE pulses too.
Also pins 7 & 3 of U1950 should pulse in such case.

Next, check all SPI termination resistors and traces around U6100.