-
For $29/mo, we provide access to advanced level technicians who will answer your questions on any Macbook board related matter to the best of their knowledge promptly & walk you through how to solve your problem so you can deliver a working board to your customer.Subscribe Now
820-3023-A Liquid damage. No PPVCORE_S0_CPU_REG or _AXG_REG
- Thread starter Paul Daniels
- Start date
Paul Daniels
Super Moderator
Waiting on replacement SMC from donors. Reflowing, and reballing produced no change.
"U7400:2 TON is ~0.1V and PPVIN_S0_CPU (~8.5V) is present on the other side of R7402"
Pin2 should drop to 0.5V aprox when CPU power supply works.
If doesn't work, pin2 should go back to 8.5V.
0.1V could point to bad U7400; did you change it?
Pin2 should drop to 0.5V aprox when CPU power supply works.
If doesn't work, pin2 should go back to 8.5V.
0.1V could point to bad U7400; did you change it?
Paul Daniels
Super Moderator
I did, same outcome. I would have liked to had access to a data sheet on this because it'd be interesting to see if the chip uses the TON pin as a status indicator too (ie, pulls it low to indicate a fault).
Look the datasheet for other buck-converter controller chip.
Many have the same TON pin and you will see it has totally different function (it is not output at all).
Many have the same TON pin and you will see it has totally different function (it is not output at all).
Paul Daniels
Super Moderator
Would be nice to have a working reference. No donors of this model on hand, awaiting supply. I agree the TON pin voltage is a bit strange, unfortunately without a comparison on hand I'm unable to ascertain if that's normal or not for this model ( but yes, it's a flag in my mind ).