MBP 2020 A2251, 820-01949, 5V 30mA

[MicroSMD Lab]

This device came in liquid damaged. It was in what seems like a bootloop every 30 seconds with the fans spinning full speed and getting 20V. The liquid damage was only to the Right speaker amp area. I cleaned up, replaced one capacitor and reballed U6550. After that I only get 5V 30mA on all ports. PPBUS_G3H is 0.11V and 13.4ohms to gnd. I get the same voltage readings on all ports
PP20V_USBC_R_VBUS = 5.19V
PP3V3_UPC_R_LDO = 3.41V
PP1V5_UPC_LDO_CORE_R = 1.57V
PP1V8_SLPS2R = 0V
PP3V3_G3H_RTC = 0V
PPHV_INT_G3H_R = 5.18V.

I read on another post (stated by Piernov) that low ohms on PPBUS_G3H could be short on high side CPU mosfet so I measured around the CPU mosfets and PPBUS_HS_CPU is also 13.4ohms to gnd.

[mon2]

Re: MBP 2020 A2251, 820-01949, 5V 30mA

Power down -> remove fuse F7000. Meter in resistance mode.

Check the resistance on both sides of F7000 SMD pads on the logic board.

Where is the low resistance to ground ? On the producer side (ISL) or consumer side of PPBUS_G3H rail ?

If the producer side is no longer a low resistance, power up again and check the voltage of PPBUS_G3H. Post each measurement.

[MicroSMD Lab]

Re: MBP 2020 A2251, 820-01949, 5V 30mA

Thanks for the very quick response mon2! The low resistance is on the consumer side (pin 2)... I fear the worst

[mon2]

Re: MBP 2020 A2251, 820-01949, 5V 30mA

After you have removed the fuse F7000, what is the voltage at the start of this fuse pad with the adapter ?

You are checking the PPBUS_G3H voltage (producer side).

[MicroSMD Lab]

Re: MBP 2020 A2251, 820-01949, 5V 30mA

12.29V on producer side

[mon2]

Re: MBP 2020 A2251, 820-01949, 5V 30mA

Do you now see 20V on the power delivery (USB C meter) from your adapter ?

[MicroSMD Lab]

Re: MBP 2020 A2251, 820-01949, 5V 30mA

Still 5V but 20mA now, same on all 4 ports