Macbook Pro A1707 - Dead - Battery 'popped'

[AdrenalinTL]

Hi Peeps.

Just a quick question please as I am by no means an Apple fundi at all.

Can a 'popped' battery cause the Macbook to be completely dead? Client said the battery definitely popped. It doesn't look swelled or anything but it doesn't switch on at all. No lights, no fans, nothing.

Also, using a 85W original Apple charger. That is working for sure. Does it need more wattage?

Don't want to go buy a battery for no reason.

Client is adamant is worked before the battery popped and I can't see any damage what so ever on the board or anywhere else.

Thanks

[mon2]

Someting popped if they heard such a noise.

Was this same power adapter used previously with success to power this laptop? Being USB Type C, you have options but recommended to test with a branded 100W USB Type C (Anker is good but there are others) + 100W rated USB Type C cable. Such a cable will have the required e-marker IC inside the hood of the cabling to permit the 20v @ 5A power delivery (PD) contract to be negotiated.

What does the USB Type C meter show for the voltage? current draw?

What is the voltage to ground of PPBUS_G3H ?

If you disconnect the battery and power up, does the logic board boot? What is the voltage & current draw on the power adapter without the battery? PPBUS_G3H voltage?

[AdrenalinTL]

Not sure if that was the original charger. The guy has a bunch of them he says. I am going to get another one from him tomorrow or Saturday.

Anyway, I presume PPBUS_G3H is the P7000/1 chip? If it is, then it's measuring 0.03V with multimeter set to 20V. Bit new to all this.

I honestly think it might be the charger, so am going to first get one tomorrow before I dive in head first any further.

Also don't have anything to measure the Type C voltage with right now.

[mon2]

Always a great idea to test with a known good adapter. Internet is showing 87W recommended power adapter (or higher) for this model. Be sure if you use a 3rd party adapter that the vendor is of quality AND the mating USB cable is capable of supporting 100W (as a minimum) else the power package will be throttled.

If you wish, remove all power, meter in resistance mode -> measure the resistance to ground of the same PPBUS_G3H rail. If there is a low resistance on this rail then someone is shorted. The low voltage may be due to the external power adapter not operating. As a power on default, the adapter should output 5 volts.

[AdrenalinTL]

Alrighty, finally got around to testing with a good charger. 140W original Apple. No good. Still dead.

My main question is, will the macbook power on if the battery is disconnected? I know Apple devices are very fussy with things.

[mon2]

Carefully measure the voltage to ground of

PPBUS_G3H @ Fuse F7000 or F7001.
PP3V3_G3H @ L6900.

Also measure the above points of interest by checking each pin on D6902 (dual common cathode diode) - measure each pin to ground.

What are the measurements?

[AdrenalinTL]

Thanks for reply.


F7000 and F7001 measure 0.09V.

D6902 pins

1 - 0.03V
2 - 0.06V
3 - 0.05V

Just for extra confirmation, I took the laptop to the original owner, who I know very well. He was using it, heard the battery pop, or what he says was the battery, then carried on using it and the battery life obviously wasn't as great, and then got a new laptop and put this one away. I also used his 140W charger with no luck.
Also bouht a new battery because if all else fails I would probably need it in any event. Still no luck with power at all. This thing is stone dead.

[mon2]

The board is missing PPBUS_G3H. Remove all power / disconnect the battery. Measure the resistance (not diode mode) of the PPBUS_G3H rail @ F7000/F7001.

What is the resistance in ohms? If the resistance is too low, there is a shorted component on this rail. Moving forward, flux and carefully remove each of these fuses so that we can isolate the producer side (ISL regulator) and the consumer side (downstream) of PPBUS_G3H.

Then power up again and measure the voltage this time to ground on the PCB pads. Do you now have a stable PPBUS_G3H rail on the producer side without a load?

[AdrenalinTL]

That was with the board completely removed. No power. Should it have had power connected?

[AdrenalinTL]

Wow must be honest this is a bit high level for me.
f7000 and 7001 both measure 1,8ohms when multimeter is set to 200 ohms.

Will wait for your reply before removing the components.

[mon2]

Can you confirm that one meter probe is one either fuse and other meter probe is to ground?

[AdrenalinTL]

I think so?

Sorry this is very amateur but can the gold plated part of the mobo ground as per below?

When to ground, it measures 0.

[mon2]

Yes. The round plated holes are intended to serve as ground connections to the chassis. There is a short to ground on this rail and this is causing the rail to turn off.

Continue to measure the resistance as follows:

One meter probe on either one of the fuses (F7000/F7001) and the other meter probe to any grey inductor on the board. Inductors will be with 2 leads - select a side. Each inductor represents another power rail. We are checking now to see if there is a defective highside mosfet. You will know this when there is a low resistance from the fuse to the inductor under test.

List any suspects and show where on the board you see the low resistance - if at all. Largest concern is the possibility that the CPU power rail is the one with a defective high side mosfet. At that point, this board is a no fix since the CPU very likely was hit by the high voltage created by PPBUS_G3H. The CPU requires usually a 1v or lower rail to operate.

Summary: One meter probe always at the fuse (F7000/F7001) with other meter probe on any inductor. Continue to test each inductor.

[AdrenalinTL]

Thanks,

Ok, measured all. All seem to be testing OK besides the one I have looked at here in the pic. Measuring 0.



Thanks for your patience so far. I know I am still asking a few things that I could be learning myself. Time just isn't on my side right now.

[AdrenalinTL]

Is this a no-go then?

[AdrenalinTL]

Uh, hello?

[mon2]

In post # 14 - how was this measured? In resistance mode with the meter probes across the 2R7 (L7030) inductor leads? If yes, then the resistance will be close to 0 ohms because this is a long run of wire = coil of wire.

Or is this the resistance to ground = 0 ohms? Not be confused with 'OL' = over limit and then you must select a higher resistance scale on your meter.

If this rail is at 0 ohms to ground then there is a shorted part on this rail.

Test in DIODE mode and compare the value to the attached. Meter in diode mode. Red meter probe, yes red to ground. Black meter probe on either side of this same inductor. What is the measurement? If close to 0 then there is indeed a short on this rail.

In diode mode, a non-shorted rail should be as per the attached diagram = 0v462.

[AdrenalinTL]

Thanks,

Yes absolutely 0 ohms. All others measure and the number keeps going up.

In diode mode the other inductors measure and give a beep. 462 shows a small measurement that drops to 334 to ground and then doesn't give a beep at all.
Same for 237, 413, 55. Highest on top left one @819 and lowest one at 129 on "326" as per your pic.

[mon2]

Both Q7030 and Q7040 dual mosfets are suspects since they both contain low side (switching to ground) mosfets.

You have a few options but suggest the following:

1) if you have flux, hot air and patience, consider to flux one side of this inductor so that it can be lifted off the board. One leg only is required to isolate which side of this circuit is shorted. Hoping it is not both but you will know soon enough.

2) After the one leg is lifted, test the inductor PCB pads to ground again and check if the short is removed or not. The side that remains to be shorted should have the dual mosfet replaced. Measure the resistance to ground on each step of this replacement process.

3) Plan B is to flux either one of the dual mosfets (Q7030 or Q7040) -> remove the part off the board and test if the short is gone or not. Repeat with the other mosfet if the short remains.

One of these dual mosfets is leaking to ground.

[AdrenalinTL]

Apologies for the very lengthy timeframe for replies. Rework station just wasnt doing it for me so I got a new one and made semi light work of the inductor whereas before I struggled badly to get 1 leg off.
That and work is just crazy atm.

Anyway....

Both Q7030 and Q7040 dual mosfets are suspects since they both contain low side (switching to ground) mosfets.

You have a few options but suggest the following:

1) if you have flux, hot air and patience, consider to flux one side of this inductor so that it can be lifted off the board. One leg only is required to isolate which side of this circuit is shorted. Hoping it is not both but you will know soon enough.

2) After the one leg is lifted, test the inductor PCB pads to ground again and check if the short is removed or not. The side that remains to be shorted should have the dual mosfet replaced. Measure the resistance to ground on each step of this replacement process.

1 side measures a reading, and the other shows 0.