MacBoo Pro Early 2015 820-4924-A

Mario Yiannakou

New member
A bit of history. Customer spilled ice tea on his keyboard and the only way it would power on was by plugging in the mag charger. I changed the keyboard then put the board into the ultrasonic cleaner, rinsed in alcohol and left to dry out.

Now I only get green then orange light on the charger but no fan spin. CPU does not warm up.
PPBUS_G3H is reading as 12.56V. Have checked ALL power rails for short to ground but found none.

WTF have I done. Please help

Thanks
 
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Mario Yiannakou

New member
I'll get those voltages for you later as I've just rinsed the board out again with alcohol - sorry. No other history than that already mentioned. When I attached the keyboard the board seemed to respond to an SMC reset i.e. charger light went green for a second then back to orange,
 

Mario Yiannakou

New member
Yes I know. I was just letting you know that it responds to SMC reset as I thought that would give you a little more to work with. I'll get you those voltages as soon as I can if not tonight (it's 10:30PM in London) then tomorrow. Really appreciate your help. Thanks again. M
 

2informaticos

Administrator
Staff member
"(P)M_BATLOW_L = 0.035V"
PCH will not start in this way; it requires 3V there.
Did you try original Apple charger?
 

JohnB8812

New member
BATLOW being low is your problem you're not using an original OEM charger. Get a KNOWN GOOD 85 watt magsafe 2 for testing!! Also, fan will not spin on this model until the CPU really heats up, so do not look for fan spin look for CPU VCore and an image on the screen.
 

Mario Yiannakou

New member
I'm using a genuine Apple magsafe 85w charger with a genuine Apple magsafe to magesafe 2 converter. It was working fine with this combination. The problem started after it came out of the ultrasonic. Yes I'm aware of the fan spin delay and also that the CPU should warm up (it doesn't). No display when screen attached.Thanks
I took some more readings this morning. Where should I go from here?
PPBUS_G3H12.56
PPBUS_S5_HS_COMPUTING12.56
PPBUS_S5_HS_OTHER5V12.56
PPBUS_S5_HS_OTHER3V312.56
PPBUS_S4_X2390
PPVIN_S4_TPAD0
PPDCIN_G3H_ISOL16.74
PP3V42_G3H3.43
PPVRTC_G3H3.34
PP5V_S55.02
PP5V_S40
PP5V_S30
PP5V_S00
PP3V3_S53.34
PP3V3_S40.01
 
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JohnB8812

New member
These will have issues with the magsafe 2 converters I would still say the charger is suspect because of that. Especially because the S4 Rails are missing as well as PM_BATLOW_L. Where was the original corrosion? There is a chance it needs to go through the ultrasonic a second time if the first time didn't get all of the corrosion. What is your resistance to ground on PM_BATLOW_L?
 

Mario Yiannakou

New member
Most of the corrosion was near the CPU but it was pretty gunky all over. I've already put through the ultrasonic again to be sure but no change. I've asked my customer to drop over his MS2 charger tomorrow. In the meantime resistance to ground for PM_BATLOW_L = 9.57 Kilo Ohms - reading taken from pin 2 of R1410. Thanks
 

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JohnB8812

New member
Did it even turn on before ultrasonic? If not, I would get your CPU is dead due to liquid near it and the controllers. If it did, def go with the MS2 charger next.
 

Mario Yiannakou

New member
Yes it did John. This is from my first post "A bit of history. Customer spilled ice tea on his keyboard and the only way it would power on was by plugging in the mag charger. I changed the keyboard then put the board into the ultrasonic cleaner, rinsed in alcohol and left to dry out.

Now I only get green then orange light on the charger but no fan spin. CPU does not warm up.
PPBUS_G3H is reading as 12.56V. Have checked ALL power rails for short to ground but found none."

Thanks
 

JohnB8812

New member
Hmm ok. First thing to try would be the charger. If that doesn't produce VCore, then this one might suck a little bit. I suspect their is a chance it was not quite dry under the CPU/RAM/any of the BGA chips, and it might need a second cleaning. PM_BATLOW_L is one of the sleep signals that enables the PCH to turn on, and it comes directly from the SMC. Usually, when that is missing, we have seen the 2015 boards refuse to put it out if the charger is not 100% the correct OEM charger it needs. It is also possible that something could be pulling it down or not creating it (SMC, CPU etc). This can sometimes happen due to crap under the CPU/SMC as well.
 

Mario Yiannakou

New member
I have got a brand new 45watt magsafe 2 charger here I tried but no joy so I'm guessing it would have to be 85w. I'm so sure it's not the charger but we shall see. I'm just not that lucky!
 

Mario Yiannakou

New member
His battery was pretty charged last time I checked when the machine was working. What if I plug in just the battery and keyboard. Should I be able to power up that way and would that prove it's more than just the charger?
 

JohnB8812

New member
Yes if it starts from a charged battery, then that would mean likely just a charger issue not autostarting the machine. 45 watt won't work btw only works with Airs.
 
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