MacBook A1707 820-00928-A does not stay on

[mferna14]

Hi., I am working on a MacBook A1707 820-00928-A does not stay on. It shuts down by itself after about 40~45 sec. The amps it takes is so normal .80 ~ .45 ~ .90 within this span of time & all voltages VCORE CPU core present, the CPU & GPU both get warm & then back to 20v 0.0amp. The logic board is like brand new, not even much dust on it. Upon trouble shooting, I see that 3.3V is always present but when the logic board shuts down 5v also drops to 0 & no CORE voltages present. I checked every single point of the 5v rail, physically nothing seems to be shorted. Any tips will be really appreciated. Thanks in advance

[Stephen]

Re: MacBook A1707 820-00928-A does not stay on

Have you checked if the battery is defective. I know it sounds crazy but these boards don’t like to function properly IF the battery is defective. Apple did do a battery recall back then in A1707 models. Those batteries were known to cause tons of issues. Still till this day, service recommend or replace now or etc will show signs you need to replace the battery, even if the battery cycle is very low.

[mferna14]

Re: MacBook A1707 820-00928-A does not stay on

Thanks Stephen for the reply... Now I removed the logic board & running without the battery, still the same problems. It's so intermittent, I cannot tell you. At times it stays on & never shuts off. Now I am logicially trouble shooting, this PM_SLP signal just dies out turning the logic board to shut down. Maybe some component is dried soldered causing this behavoiur. Let's see. Any more tips will be greatly appreciated.

[mon2]

Re: MacBook A1707 820-00928-A does not stay on

1) the A1707 is linked to flexgate.

2) are you testing with or without the trackpad and keyboard? Suggestion is test without both and use tweezers to power on/off to rule out the add-ons.

3) what is the voltage to ground of ppbus_g3h during normal operation and then when it shuts off?

4) after you lose the 5v rail, check the voltage to ground of the enable pin for that power rail.

5) confirm the DCin voltage that feeds into the ISL device for ppbus_g3h.

6) do test with another USB type c power adapter. Do test with other USB c connectors on this logic board. Even rotate the power head by 180 degrees to test the other side of the type c connector blade.

[mferna14]

Re: MacBook A1707 820-00928-A does not stay on

Thanks @mon2., appreciate your tips. I will check whatever you told me & last when I had it on, it stayed on till I powered it off or pulled out the power cord. See this what I am facing, problem is so intermittent, can't figure out where the problem could be. Maybe this morning I will turn on again, hopefully it will shut down so that I can measure all the required voltages. Thanks

[mferna14]

Re: MacBook A1707 820-00928-A does not stay on

Mom2 below are my finding, pls. view them. Thanks

1) the A1707 is linked to flexgate. OK

2) are you testing with or without the trackpad and keyboard? Suggestion is test without both and use tweezers to power on/off to rule out the add-ons. Not testing with any device attached to the logic board

3) what is the voltage to ground of ppbus_g3h during normal operation and then when it shuts off? 12.59V

4) after you lose the 5v rail, check the voltage to ground of the enable pin for that power rail. 0v But when on ENABLE is 3.3V

5) confirm the DCin voltage that feeds into the ISL device for ppbus_g3h. 12.59V VCC to the ISL Chip

6) do test with another USB type c power adapter. Do test with other USB c connectors on this logic board. Even rotate the power head by 180 degrees to test the other side of the type c connector blade. Did test it with another power supply in every direction