A2159 no power test (no charger)

**mon2** · 09-03-2022, 04:56 PM

Re: A2159 no power test (no charger)

Check the fuses.

You do require a suitable usb type c power adapter that can deliver the current for this logic board.

It does not have to be the Apple brand but is recommended.

A usb current meter is a must have tool to monitor the progress. Perhaps it is available in your local markets through a reseller. Many are available on AliExpress.

No, you cannot emulate the handshake performed by the power delivery controllers. There is a complex software stack that negotiates safely the best contract of voltage and current for your logic board.

The 5v type c adapter is likely not working as it is only fitted with a type c connector. This does not imply the adapter can support the power delivery specification.

It is the PD spec that offers the full details that it is powerful enough to be power this logic board. The logic board is a much heavier load than a phone.

At the office we use the CUI brand power adapter with type C and power delivery specification. Works well for a lot of units.

Search around to find a 65w-100w adapter. Then start your testing.

**marce002** · 09-03-2022, 05:50 PM

Re: A2159 no power test (no charger)

thanks mon , just because saw this interesting video, and did not believe

https://youtu.be/HJJmVY-I-OE

I have removed the board.... for now just make diode and resistance measurements, so if you want me to test RES from coils to ground, or anyone does know typical values for this board will be welcome.... for example I have

RES TO GROUND FROM:

51,6ohm F7000

**mon2** · 09-03-2022, 07:04 PM

Re: A2159 no power test (no charger)

That is a very low resistance.

Remove F7000 fuse and check if the low resistance is on the ISL (producer) or downstream (consumer) side.

**marce002** · 09-04-2022, 02:35 PM

Re: A2159 no power test (no charger)

Mon , battery removed , only board, fuse as expected : I have 60ohm in the load part (ppbus_g3h) and 2.88Mohm in the pin 1 of the fuse (PPVBAT_G3h etc).
Lets inject volt and try to check something hot? i can do ... only issue is i have lab power supply (no mac usb c for now)

thanks in advance

Attached Files

**mon2** · 09-04-2022, 04:45 PM

Re: A2159 no power test (no charger)

Yes, voltage injection is ok but...must keep the voltage low and suggest to be 1 volt or lower. This is just in case a mosfet is leaking and can kill the CPU.

**marce002** · 09-04-2022, 05:10 PM

Re: A2159 no power test (no charger)

yes mon ... it goes up to 4amp at 1v anything get noticiable hot at thos power unfortunately do not have termal camera.. so any hint here will be apreciated

**mon2** · 09-04-2022, 05:16 PM

Re: A2159 no power test (no charger)

Usually IPA is used for this case. Where you see the IPA evaporating quickly is the defective part. Do review the CPU rail and the CPU / PCH which may be an issue but is cooled by the heatsink.

Remove all power. Meter in resistance mode. Check the resistance to ground of the Vcore rail of the CPU.

**marce002** · 09-04-2022, 05:37 PM

Re: A2159 no power test (no charger)

I have :

"22ohm" at L7270 which is PPVCCSA_S0_CPU
"8ohm" at L7220 and L7210 which is PPVCC_S0_CPU

"7,2ohm" C7219 pin 2 for example which is CPUCORE_PHASE1
"1Mohm and going down" at R7215 pin2 which is pp5v_main_vcore1

i do not know if they are much of what you have asked

thanks mon

**mon2** · 09-04-2022, 05:52 PM

Re: A2159 no power test (no charger)

These are good readings for the resistance and not shorts.

You can dial up the voltage to 1v2 on your power supply used for the injection but still suggest to not go higher for safety reasons. When you do this, do you measure any voltage the cpu voltage rails?

**marce002** · 09-04-2022, 06:05 PM

Re: A2159 no power test (no charger)

ok 1.2vol ....reached 5.203 amps ...nothing noticeable warm so IPA not much usefu here... and in this scenario no volt at the previous points ...coils are at around 0.82mv 0v

**mon2** · 09-04-2022, 06:19 PM

Re: A2159 no power test (no charger)

We are trying to confirm there is no mosfet leakage into the CPU rails. Then you can consider to go higher on the injection voltage. It appears that the cpu rail is not leaking but consider to wait on advice from others before dialing up the voltage. Something is eating up this current and should be heating up. Of course, higher voltage will crank the heat even more.

We use a voltage injector that claims to support 20-30A ( need to confirm) so we have seen it to cause a tantalum to split apart with a few pulses at 1v.

Can your power supply support higher current but remain at 1v ?

**marce002** · 09-04-2022, 06:41 PM

Re: A2159 no power test (no charger)

ugh ok... I have a 5A limit .... saddly

**mon2** · 09-04-2022, 07:10 PM

Re: A2159 no power test (no charger)

Wait on others to comment but it may be ok for your case to select a higher voltage for the injection. As noted, we just to be 110% sure that you do not have a fault downstream on this rail like a leaky mosfet that can cause permanent damage to other low voltage parts. So for example, if you decide to dial up to say 2v and the CPU max is 1v2 and the rail for the CPU is leaking, the CPU is at risk of being damaged.

**marce002** · 09-04-2022, 07:19 PM

Re: A2159 no power test (no charger)

yes understood... I will try higher volt , provided this is 12v rail right? it is ppbus_g3h rail shorted to gnd...and low probability for cpu rail to be damaged by misfit..... also verify all rossmann an others similar issues on videos related... if anyone have ani idea please since it is a 2019 board and is the newest I received and little or none experience on them this

**marce002** · 09-05-2022, 07:22 AM

Re: A2159 no power test (no charger)

ok after some shorted cap reolacement cd7m1 now I have 65ohm in ppbus (still low?) and 0.007mah from usb 5v only from power supply.
And injecting 1Vol to ppbus as before now I have just 0.015mah draw, no more 5A

And I have 0,012mah with fuse f7000 back in place, (from usb 5v )

Attached Files

**mon2** · 09-05-2022, 08:02 AM

Re: A2159 no power test (no charger)

Good. The PPBUS_G3H resistance to ground still sounds low but is not a short.

With F7000 installed, what is the voltage of PPBUS_G3H when you attach a power adapter?

**marce002** · 09-05-2022, 12:43 PM

Re: A2159 no power test (no charger)

only 298mv so nothing.... beware i have only usb with 5v no apple adapter yet... being rude and injecting 5v to that rail ppbus_g3h i see that U6903 gets hot..
So for now i can do RES and diode mode testing, and with an usb "C" standard cable and my lab power supply feed from the ports from 5v to 20v....
I wonder if only using 5V , will I have 12v ppbus_g3h?

**mon2** · 09-05-2022, 01:28 PM

Re: A2159 no power test (no charger)

I think that are too many variables at play.

1) Do source a suitable official power adapter for USB Type C laptop servicing.

2) Do source a USB Type C meter. I think there are many on the market but we like this one the best so far:

T66C (have not yet used the Bluetooth feature but is a nice & with a vibrant display)

https://www.aliexpress.com/item/3296...d=ynkBGAkk4VSt

3) Remove F7000 and check if the ISL9240 is able to offer any output at the F7000, pin # 1 PCB pad. What is the voltage if PPBUS_G3H without the fuse?

4) What are the full markings of your power adapter being used ? Does it support 'power delivery specification' ? If not, then this is just a simple 5V power supply with a Type C connector.

Based on the above assumption, the logic board may be just refusing to proceed.

5) The ISL9240 & ISL9239 (previous generation) are buck/boost regulators. That is, they can take a low input voltage -> boost it to a higher voltage like 12v or vice versa. Take a high input voltage (ie. 20v) -> lower it to a voltage like 12v6 (BUCK mode).

Before we can proceed, the PPBUS_G3H must work to offer the ~12v rail. This is the first step but may be blocked due to the wrong power adapter being used.

Perhaps check your local Amazon store for a quick delivery.

6) Confirm the voltage of PPDCIN_G3H (left side of ISL9240; page 64 in schematics). What is this input voltage with your adapter ?

**marce002** · 09-05-2022, 01:50 PM

Re: A2159 no power test (no charger)

ok Mon ok ... while my missing stuff is being ordered, i will check what I do have with no fuse f7000, because from the power seq diagram attached, it is clear that ppbus is present with just 5v usb cable right? it states VALID EXTERNAL POWER SOURCE, BATTERY OR CHARGER >4.0V
i also have its battery , but i do not know if charged

Attached Files

A2159 no power test (no charger)

A2159 no power test (no charger)

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