Bizarre Repair 2020: 13" Macbook Pro (A1502, 2015) Filled with Lotion

[matthewgreene]

Greetings Forum,

I'm new here, new to MacBook repair, and new to cleaning out electronic devices filled with lotion.

I've been microsoldering for about 6 months, and have started up a device repair business where I live in Western North Carolina. I got into this so that I can always have a working iPod classic, and not many places will solder on those 30 pin connectors when you break them. I attended PBRS at iPad Rehab, downloaded and viewed Mike H.'s (from microsoldering.com) microsoldering course, and have been pretty much soldering something every day since getting into this.

Though I've gotten pretty good at reading phone schematics, the MacBook schematics are new to me. I did go through the Rossman Repair Training Guide, and it's certainly helpful, but I'll need to a bit to get up to speed.

As stated above, I recently received a MacBook Pro that was filled with lotion on the MagSafe 2 adapter side. I've pulled it apart, cleaned out the lotion, washed the board and MagSafe connector in the ultrasonic bath, and reassembled. During this process, I realized that the microphone connector had shorted so badly that the ribbon cable had actually fused with the connector. In order to eliminate this as a source of potential short, I removed that connector from the board.

This is where the computer is at: plugging it in results in expected behavior from the MagSafe adapter: the light turns on and responds. The fan kicks on immediately and runs at what appears to be full speed. Disconnecting the DC power and hooking up the battery will result in more-or-less the same behavior. No boot, obviously, and no chime.

Looking at the board while its running with the thermal camera shows no obvious hot spots. I can see a warm spot in the flash drive, the fan connector, and many of the ground connections on different components are warm. Based on this, I'm hypothesizing that something, somewhere is shorted to ground. I'm just not sure where to start.

Based on the Rossman Repair Training Guide, I feel confident in stating that PPBUS_G3H is functioning properly, and I believe my next step is to assess the state of the SMC, and/or check all of the G3 always hot lines, though I am totally not confident in this plan.

Any thoughts or insights that can be provided would be helpful and much appreciated, especially from those of you who've cleaned lotion out of MacBooks in the past.

Thanks.

 

[2informaticos]

First of all, welcome to the forum!

If fan spins, forget about checking G3H lines; you are already in S0 state!

Disconnect any thing form the board; no RIO flex, SSD, trackpad flex, nor other cables.
Keep only DCIN board and use an USB device to test for activity; more information available on the forum.

If fan started high spin, there is a problem with at least one SMC sensor.
Don't worry about that yet.

We need you to post voltage on all big coils.
If board stays on, then should not have any short...

 

[matthewgreene]

Forgive me for asking what are probably basic questions.

1. This first one is probably ridiculous, but I have to ask: I can assume the board stays on if the orange light on MagSafe stays lit, is that correct?
2. What kind of values should I be posting, for example, L7630 is pretty consistently testing around 1.5 mV with my auto ranging DMM. Is that 1.5 important. For the most part, with the exception of L7630, which is pretty consistently around 1.5mV, everything else is given below:

L7630 -- 1.4mV
L7310 -- 100 mV
L7320 -- 30 mV
L7430 -- 32 mV
L7710 -- 46 mV
L7720 -- 46 mV
L3095 -- 25 mV
L7195 -- 23 mV
L7520 -- 0
L7130 -- 5.5 mV
L7870 -- 0

I'm not sure if those are all of the big coils; if not let me know.

Thanks for your help.

 

[2informaticos]

"What kind of values should I be posting "
You can guess many voltages because the name of their power rails.
What do you expect to get on L7630 (1V05_S0_REG)?
Sometime the voltage appears in the top of the page; L7430 (DDR_S3_REG) marked clearly on top as "1.2V S3 Regulator".
Mahe use of your logic, please...

"I can assume the board stays on if the orange light on MagSafe stays lit, is that correct? "
NOT at all.
In time you will find working boards which don't have Magsafe light.
Such board will not charge the battery, so still need to be repaired somehow.

"Is that 1.5 important. "
Is completely irrelevant, as 100mV too.

"The fan kicks on immediately and runs at what appears to be full speed
-----------------
Looking at the board while its running"
You've said the board is running.
Also, is no possible to have fan spinning, if no 5V_S0 present, at least.

No matters which state is the board, we need some volatges; not irrelevant mV please.
To be more specific, post exact PPBUS_G3H voltage and 3V3_S5/SUS.
Also check PM_SLP_SUS_L, as other PM_SLP_Sx_L signals too.

 

[matthewgreene]

Thanks again for your help. I apologize for my ignorance here; forgive me, as I come from a research background, and in my experience it's better to be complete than not.

I'm pretty familiar with Boardview files and have better than rudimentary schematic reading skills, so I am aware of the voltages that should be on those lines; again, in my experience it's better to be more complete than not.

Regarding the lines you mentioned:

PPBUS_G3H -- 12.55 V
PVP3V3_S5 -- 3.33 V
PM_SLP_SUS_L -- 3.32 V
PM_SLP_S0_L -- 5.14 V edit
PM_SLP_S3_L -- 3.3 V
PM_SLP_S4_L -- 3.3 V
PM_SLP_S0_L -- 3.3V

 

[2informaticos]

If you have high level for PM_SLP_Sx_L signals, you should have almost all voltage rails present, including S0.

BTW, please correct the error about PM_SLP_S0_L in your last post.
It is not very important at this moment, but I wonder how can you get two different voltages on the same line...

Post again voltages on the coils before mentioned.

 

[matthewgreene]

Okay...
Not sure what happened when I measured these the first time around. My bad and my apologies to you. I just now changed the battery in my DMM; perhaps that has something to do with it.

Please note the edit in the previous post regarding 5.14 V on PM_SLP_S0_L.

L7630 -- 1.05 V
L7310 -- 0 V
L7320 -- 0 V
L7430 -- 1.2 V
L7710 -- 0 V
L7720 -- 5.14 V
L3095 -- 0 V
L7195 -- 5.43 V
L7520 -- 5.14V
L7130 -- 12.32 V
L7870 -- 1.5 V

 

[2informaticos]

"Please note the edit in the previous post regarding 5.14 V on PM_SLP_S0_L. "
Still bad to get 3.3V and 5.14V at same line, believe me!
I suppose you got confused and there are two different signals instead.

Looks like you get many voltages, including S0 ones.
No pulse at all at L7310/20?
Check pins 7 & 3 of u1950.

 

[matthewgreene]

"Please note the edit in the previous post regarding 5.14 V on PM_SLP_S0_L. "
Still bad to get 3.3V and 5.14V at same line, believe me!
I suppose you got confused and there are two different signals instead.

Looks like you get many voltages, including S0 ones.
No pulse at all at L7310/20?
Check pins 7 & 3 of u1950.

Okay, sorry about that; my fault again; PM_SLP_S0_L is 3.3 V

I've check both 7310/20 again--at least a dozen times--and nothing.

No power at pins, 7 or 3, but just to confirm that everything was working as expected based on what is known thus far, I confirmed the 3.42 V on pin 8.

 

[2informaticos]

Do you get steady voltage at L7720, L7430, L7870 and L7630?
If yes, ALL_SYS_PWRGD should be high too.

 

[matthewgreene]

Do you get steady voltage at L7720, L7430, L7870 and L7630?
If yes, ALL_SYS_PWRGD should be high too.

Okay... Checking them all again:

L7720 -- 5.14
L7430 -- 1.20
L7630 -- 1.05
L7870 -- 1.50
ALL_SYS_PWRGD -- 0

That said, I followed ALL_SYS_PWRGD, which is when I realized that U1860 is actually missing. I'm going to have to go through and look at all of these pads that have no components on them, and confirm which are NOSTUFF and which are not.

I feel better that the measurements I was taking have some basis in reality.

Thanks for your help.

 

[2informaticos]

ALL_SYS_PWRGD is the sum of several power goods signals.
The reason, one power supply doesn't work properly, or fails its power good.

Start removing Q8150; is a redundant protection amd you can leave it out...

BTW, any reason to quote an entire post visible few centimeters above???

 

[matthewgreene]

Okay... I replaced a bunch of stuff on this board, and I have 1.8 V at both L7310/20

Pins 7 and 3 on U1950 - 3.4 V
ALL_SYS_PWRGD - 3.3 V

What are my next steps here? Thanks for your help.

 

[2informaticos]

So the board stays on now, but no activity at all?
Did you check for USB activity at least?
PLT_RESET_L is high?

 

[matthewgreene]

Prior to my message yesterday, I replaced a few components and this is the state of the board currently. I haven't tried anything other than replacing those components; now that I've replaced them, I have power back at those specific components. Should I put the board back in the case and try to boot it? If so, do I need the battery to boot? I'm not sure if the battery was damaged. Also, what if the top case is messed up, like the keyboard doesn't work, is there a way to boot in that scenario?

 

[2informaticos]

This is iCore platform, should boot automatically when proper charger is connected.
Work with board alone on the desk; no battery needed, uet.
Use an USB mouse to check for USB acrivity.

 

[matthewgreene]

Nothing with my USB mouse, in that that laser didn't come on, but checked with my USB ammeter, and have 5.25 V @ USB

 

[2informaticos]

USB power and activity is not the same thing!

"PLT_RESET_L is high?"
You can try known good BIOS now...

 

[matthewgreene]

PLT_RESET_L is 3.3 V

Pardon my total ignorance once again here, but can you please provide some clarification regarding 'trying a known good BIOS,' please? I'm not sure how to do that. Again, my apologies for my total ignorance here.

 

[2informaticos]

You need to reflash the BIOS, located on the SPI chip U6100.
I guess you don't have Medusa programmer, so you need to remove the chip and attach it (with proper adapter) to an USB programmer.