Brand: Apple
Model: A1990
Board number: 820-01041
Problem: I am not an Apple kind of guy to start with. But I am quite experienced with motherboard repairs in general. So the laptop is stuck with 5v 0.250A and does not negotiate 20v. Same symptom on all 4 USB C ports. When charger is plugged the amps start at around 0.060 then go trough: 0.100 - 0.180 - 0.230 - 0.244 and stay like this. Laptop responds to the power button: once I hold it long enough current goes down to 0.060A and then up to previous levels.
Board clean, no liquid damage, no corrosion. No shorts on any of the coils. PPBUS_G3H present, no S5 rails. I figured I will try DFU revive.
I followed this manual: https://logi.wiki/index.php/DFU_Mode_Restore_(Macs)
To put the machine into DFU mode I use both keyboard method (with holding the keys) and also I used jumper method.
So I created a jumper with a switch between FORCE_DFU and 1.8v. When I short the FORCE_DFU with 1.8v and plug the charger to the USB C port on the left hand side of the laptop, closest to the touchpad I do get then max 0.057A current draw and also DFU_STATUS goes up to 1.8v indicating that the DFU mode is active. But when I do the same just instead of a charger I plug in the host computer (iMac 2019) the target machine is not being seen by the Apple configurator 2 despite DFU_STATUS being high and indicating DFU mode is active. I tried the same with charger plugged in to another USB C port.
Few facts:
1. If I short FORCE_DFU with 1.8v the DFU_STATUS goes up to 1.8v only if I plug the charger to the left hand side, closest to the touchpad USB C port. In case if I plug the charger to any other port DFU_STATUS remains at 0v.
2. If I first plug the target (faulty) machine to the host (iMac) and then connect the charger (to any other USB C port) that charger negotiates 20v. But current draw from the charger is 0A.
3. My host machine is iMac 2019 with Ventura onboard and I think Apple Configurator 2.16. I can not use the latest one from the apple store as apparently it is only compatible with Sonoma?
4. I use original USB C to USB C Apple charging cable.
Any advise?
Thank you.
Model: A1990
Board number: 820-01041
Problem: I am not an Apple kind of guy to start with. But I am quite experienced with motherboard repairs in general. So the laptop is stuck with 5v 0.250A and does not negotiate 20v. Same symptom on all 4 USB C ports. When charger is plugged the amps start at around 0.060 then go trough: 0.100 - 0.180 - 0.230 - 0.244 and stay like this. Laptop responds to the power button: once I hold it long enough current goes down to 0.060A and then up to previous levels.
Board clean, no liquid damage, no corrosion. No shorts on any of the coils. PPBUS_G3H present, no S5 rails. I figured I will try DFU revive.
I followed this manual: https://logi.wiki/index.php/DFU_Mode_Restore_(Macs)
To put the machine into DFU mode I use both keyboard method (with holding the keys) and also I used jumper method.
So I created a jumper with a switch between FORCE_DFU and 1.8v. When I short the FORCE_DFU with 1.8v and plug the charger to the USB C port on the left hand side of the laptop, closest to the touchpad I do get then max 0.057A current draw and also DFU_STATUS goes up to 1.8v indicating that the DFU mode is active. But when I do the same just instead of a charger I plug in the host computer (iMac 2019) the target machine is not being seen by the Apple configurator 2 despite DFU_STATUS being high and indicating DFU mode is active. I tried the same with charger plugged in to another USB C port.
Few facts:
1. If I short FORCE_DFU with 1.8v the DFU_STATUS goes up to 1.8v only if I plug the charger to the left hand side, closest to the touchpad USB C port. In case if I plug the charger to any other port DFU_STATUS remains at 0v.
2. If I first plug the target (faulty) machine to the host (iMac) and then connect the charger (to any other USB C port) that charger negotiates 20v. But current draw from the charger is 0A.
3. My host machine is iMac 2019 with Ventura onboard and I think Apple Configurator 2.16. I can not use the latest one from the apple store as apparently it is only compatible with Sonoma?
4. I use original USB C to USB C Apple charging cable.
Any advise?
Thank you.
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