MacBook Pro A1990 stuck at 5v .592 amps

[Fisher8865]

Hi guys




I have a MacBook Pro A1990 that takes 4.9 Volts and .592 to .615 amps on one port. The other port on the left side power cycles with about the same amount of volts an amps but quickly power cycles. The same thing happens on the other side but opposite. So on the left side the bottom port stays on and on the right side it's the top one. I think it is a CD3215 chip but I am not sure how to test it or where to get one. I have checked for voltage at ppbus_g3h and it has 12.6 V which is also on fuses f7000 and f7001 I checked pp1v2_s3 and it has 1.2 V then I checked pp1v2_s3 and it is stuck at 0 and I didn't know how much further down the checklist I should go. I don't know if I'm getting sidetracked with that or not. Also the mosfet (q7065) which is near the battery connector it has 12.6 V on one side and 150 mili amp on the other which is on the connector side and it also has 150 mili amps on it as well. I have the board removed from the laptop doing this testing. Any help is greatly appreciated.

[Fisher8865]

I thought that I should also mention that I looked over the board under a microscope and found no physical signs of heat or damage no liquid damage. There are also no shorts I could find and looking at it under a thermal camera only showed the cd3215 chip getting warm after a few mins. It’s been a challenge for me and any help is appreciated.

[reformatt]

Review the wiki here with power sequence for T2

https://repair.wiki/w/Apple_T2_platform

Old wiki guide for A1990 here:

https://old.repair.wiki/w/A1990_2018...ar_MacBook_Pro

Rule out shorted caps near the edges on either side of the board. Most commonly affected are the SSD 2.5V power rails due to dust accumulation from the fan intakes.