Macbook Pro 13'' 2017 A1708 Won't power on with battery connected.

[mon2]

Re: Macbook Pro 13'' 2017 A1708 Won't power on with battery connected.

I don't have access to the schematics right now, waiting on junior to get his haircut. Check the common signals between the battery and the display.

Suspecting the smbus lines.

Remove all power. Meter in diode mode.

Remove the display.

Red meter probe to ground.
Black meter probe to smbus SCL line. Measurement?

Repeat for the SDA line.

Now connect the display. Repeat the above measurements. All with no power and meter in diode mode.

[platinumsteel]

Re: Macbook Pro 13'' 2017 A1708 Won't power on with battery connected.

okay so on diode mode with the display disconnected 0.470v on SDA and 0.471v on SCL.Same measurements with Display connected.
I ended up trying out another display and still getting the exact same symptoms.

[mon2]

Re: Macbook Pro 13'' 2017 A1708 Won't power on with battery connected.

These are good readings in diode mode.

There are numerous I2C bus connections on the LCD display connector.

With no power, meter in DIODE mode.

Red probe to ground.
Black probe on point to test -> continue to test each and every I2C line.

See attached. If you have similar readings for each of these I2C lines, proceed to test the other pins on the LCD display connector WITH the display attached.

Someone is tanking the logic board once the display is attached.

[platinumsteel]

Re: Macbook Pro 13'' 2017 A1708 Won't power on with battery connected.

Hi mon i spent days and nights troubleshooting all kind of different scenarios to figure out what the hell is going on with this board.As soon as it is about to show boot logo on screen it shuts down kinda like when u hold down the power button.I see a split second flash on screen.I tried everything in the book.And still no hope.I narrowed it down too this. Once the board is in a chasis it will not complete a boot with picture with screen and battery attached. if I take it out of the chasis and connect the screen and battery only it will complete the boot and give me picture.I ruled out everything else and i mean everything. I also tried to put some paper under the entire board but still no hope.I switched chasis nothing changed.I can't begin to state every component i changed prior.lol. I changed smc 3 times. the ISL. 4 main components of the backlight circuit. Backlight IC and Mosfets. I even changed the battery Mosfet.One thing tho if i remove the backlight fuse with screen connected it completes the boot cycle.So thought it was related to backlight which is why i changed all main components for the backlight circuit. I don't know what to try again. Anything you can point out to test or try ?

[Stevedb]

Re: Macbook Pro 13'' 2017 A1708 Won't power on with battery connected.

Hi maybe a gues but i would look into lidswitch area . I think something wrong there.

Greetings
Steve

[mon2]

Re: Macbook Pro 13'' 2017 A1708 Won't power on with battery connected.

This model and age is affected by the flex gate issue.

Remove the display cables.

Boot normally. Are you able to toggle the caps led on the keyboard after booting and waiting the time for the login screen?

[platinumsteel]

Re: Macbook Pro 13'' 2017 A1708 Won't power on with battery connected.

Yes if i remove the display cable i will boot normally. I'll have cpuvcore. And also I get external display.I have 3x screens.2 of them are for testing.2 of them Got a lot of scratches and dents. But they work fine.And the other one is a brand new screen I ordered which came about 2 weeks now.All screens do the same thing.
Thanks a lot for the guess Stevedb.That is the only area i didn't check out.I just woke up and now about to check out this lidswitch thingy.

[platinumsteel]

Re: Macbook Pro 13'' 2017 A1708 Won't power on with battery connected.

Okay so am reporting back on the success now of this board. Believe it or not it was a bad bios or Bad MeRegion. I downloaded a Clean ME Region from peste on this forum and slapped it in.And all problems disappeared. It's working fine now with everything connected.Was able to learn a good bit of things to check in this thread about the sda/scl lines very grateful for that.Thanks to everyone.

[mon2]

Re: Macbook Pro 13'' 2017 A1708 Won't power on with battery connected.

Well done. Thanks for your update.

[arevut]

Re: Macbook Pro 13'' 2017 A1708 Won't power on with battery connected.

Okay so am reporting back on the success now of this board. Believe it or not it was a bad bios or Bad MeRegion. I downloaded a Clean ME Region from peste on this forum and slapped it in.And all problems disappeared. It's working fine now with everything connected.Was able to learn a good bit of things to check in this thread about the sda/scl lines very grateful for that.Thanks to everyone.

Hi, Could you please provide a link to this forum thread?

[arevut]

Re: Macbook Pro 13'' 2017 A1708 Won't power on with battery connected.

Well done. Thanks for your update.

Hi, I have the close problem. Motherboard do not want to start with the battery connected if I keep the laptop closed and disconnected from external power for a day or so. After reconnecting the battery, it can to start some amount of time. I tried to disconnect keyboard, trackpad, reset SMC, replaced the battery to the brand new one - gave no result. Motherbord lookes great like just from factory. No any tracks of liquid damage, all is clean. But there is some strange thing. The PPBUS_G3H is only 10,68V. On the gate of Q7065 is 2,46V. What to do next? Which direction to move in?

[mon2]

Measure the voltage to ground of each pin on the battery connector with both, the battery and power adapter attached. Post each measurement.

[arevut]

Measure the voltage to ground of each pin on the battery connector with both, the battery and power adapter attached. Post each measurement.

Now it is still in the working mode. It boots without any problem. Measurements will probably need to be taken, when it switches to the mode from which it no longer starts without the battery disconnected?

[arevut]

Measure the voltage to ground of each pin on the battery connector with both, the battery and power adapter attached. Post each measurement.

J6951 connector with both battery and power adapter attached:

pin 2: SMBUS_SMC_5_G3H_SCL = 3.408V
pin 3: SMBUS_SMC_5_G3H_SDA = 3.408V
pin 7: SYS_DETECT_L = 0.016V

Now the motherboard does not start
Current consumption of the board with all parts attached is 1.707A.

PPBUS_G3H = 11.25V with attached power adapter
PPBUS_G3H = 10.52 without power adapter (only battery attached)

[mon2]

What is the usb type C adapter voltage? Is it 20v?

Using a suitable power adapter to power this unit? Suggest 100W with certified 100W cable.

Is the 1.7A current consumption immediate or climbs to this value? If immediate then there is likely a shorted part onboard (capacitor?).

Flux and carefully remove the fuse(S) on the ppbus_g3h rail to isolate the producer and consumer sides of this rail. Then power up again. Is the ppbus_g3h higher and stable? The smbus rail is not shorted which is good but ppbus_g3h is the wrong voltage. The isl chip may be defective or the current sense resistance is of the wrong values. Leave the fuses off til the ppbus_g3h is stable.

[arevut]

What is the usb type C adapter voltage? Is it 20v?

Yes, 20V present

Using a suitable power adapter to power this unit? Suggest 100W with certified 100W cable.

Yes, I use certified 100W cable and 100W power adapter.

Is the 1.7A current consumption immediate or climbs to this value? If immediate then there is likely a shorted part onboard (capacitor?).

Now consumption is 1.4 I think due to the battery charging. The consumption climbes to it values.

Flux and carefully remove the fuse(S) on the ppbus_g3h rail to isolate the producer and consumer sides of this rail. Then power up again. Is the ppbus_g3h higher and stable? The smbus rail is not shorted which is good but ppbus_g3h is the wrong voltage. The isl chip may be defective or the current sense resistance is of the wrong values. Leave the fuses off til the ppbus_g3h is stable.

Ok. I will try.

[arevut]

Flux and carefully remove the fuse(S) on the ppbus_g3h rail to isolate the producer and consumer sides of this rail. Then power up again. Is the ppbus_g3h higher and stable? The smbus rail is not shorted which is good but ppbus_g3h is the wrong voltage. The isl chip may be defective or the current sense resistance is of the wrong values. Leave the fuses off til the ppbus_g3h is stable.

So I got 13V on ppbus_g3h when I just simply disconnect the battery to remove the fuses.

[mon2]

What is the voltage to ground of the battery?

Remove all power / no battery. Meter in resistance mode.

Measure the resistance of the battery mosfet @ Q7065.

Measure as follows:

source (1-2-3) & drain (5-6-7-8)
source (1-2-3) & gate (4)
gate (4) & drain (5-6-7-8)

Post each measurement. We are checking if there is a leaky mosfet here.

Q7065 is a P-channel mosfet so to enable this mosfet, the gate voltage is required to be lower than the voltage being passed between source / drain pins.

[arevut]

What is the voltage to ground of the battery?

PPVBAT_G3H_CONN = 10.5V

Remove all power / no battery. Meter in resistance mode.

Measure the resistance of the battery mosfet @ Q7065.

Measure as follows:

source (1-2-3) & drain (5-6-7-8)
source (1-2-3) & gate (4)
gate (4) & drain (5-6-7-8)

Post each measurement. We are checking if there is a leaky mosfet here.

Q7065 is a P-channel mosfet so to enable this mosfet, the gate voltage is required to be lower than the voltage being passed between source / drain pins.

source (1-2-3) & drain (5-6-7-8) = 5.42K vs 157K
source (1-2-3) & gate (4) = 0.54M vs 7.8M
gate (4) & drain (5-6-7-8) = 7.3M vs 11M

*vs depending on the polarity of the probes

[mon2]

source (1-2-3) & drain (5-6-7-8) = 5.42K vs 157K

For a good mosfet, these are low resistance measurements. Carefully, flux and remove this mosfet off the board and test using the same method after the mosfet has cooled down and on your work bench. Confirm if the measurements remain this low or not.