MacBook Pro 2010 15" 820-2850 no charge, green light, powers on

[trondl]

Hello from Norway!
First post here, and first ever laptop board repair.
I repair electronics as a profession, but not much experience in this field.
Don't have fine/thin tip probes, so probing small ICs on a live boards is not safe (yet).
If you ask me to get voltage readings from a certain bus, please tell me exactly where to probe. If you have an image with a red circle, that's even better.
Have found the board view file, but not sure where to start.

Have tried googling the following symptoms, but few match my symptoms and mainboard.

History: Bought for cheap with known worn out battery, not knowing it was a cheap "genuine" battery.
Battery did charge, but veeeery slow (almost a full day, if not more).
Would not run on battery alone.
Did a teardown to apply new thermal paste and to remove dust.

Bought new third party battery (German "reputable" brand).
When installing it, I may have touched the battery socket pins on the mainboard with my fingertip on the right side (Viewed from the socket entry).
Felt a very faint tingle (oops? SMC toast?).
SMC reset both with and without battery tried. No Change.

Powered on, noticing it wouldn't charge, even when battery lower than 80%.
Won't charge when powered off either.
Green light, but no amber/orange.

I have two original 85W chargers, both tested. Same results.
Battery LED indicator gives correct readings when pushed.
coconutBattery gives correct details about the battery, except a strange serial" "-----------" etc. Possibly not relevant.

Got a replacement battery on warranty, same status.

It runs stand alone on the new battery.
Battery status in macOS is "Not Charging"

Fuse? Current sense resistor? Mosfet?

Thanks a bunch in advance!

[mon2]

Re: MacBook Pro 2010 15" 820-2850 no charge, green light, powers on

hi.

1) see attached. locate the battery connector @ J6950.

2) Meter in DC volts (20v or higher scale is ok). Measure the voltage on each battery connector pin with the battery connected & powered by the external adapter.

So,

red lead on pin # 1 (J6950) & black meter lead to ground (shield is ok) - post the voltage.

Repeat for each pin on this connectors.

3) Also interested in the voltage output of U7000 as per attachment. U7000 is the charger IC that powers the logic board and also creates the battery charge voltage. It features a current sense circuit that monitors if the current is too high or too low. If the current sense circuit is not present on the logic board due to a missing part, the battery charger will assume that too much current is being drawn and therefore, will shut off the battery charging mosfet @ Q7055.

Measure and post the readings for the points # 1, #2 and # 3.

[trondl]

Re: MacBook Pro 2010 15" 820-2850 no charge, green light, powers on

hi.

1) see attached. locate the battery connector @ J6950.

2) Meter in DC volts (20v or higher scale is ok). Measure the voltage on each battery connector pin with the battery connected & powered by the external adapter.

So,

red lead on pin # 1 (J6950) & black meter lead to ground (shield is ok) - post the voltage.

Repeat for each pin on this connectors.

3) Also interested in the voltage output of U7000 as per attachment. U7000 is the charger IC that powers the logic board and also creates the battery charge voltage. It features a current sense circuit that monitors if the current is too high or too low. If the current sense circuit is not present on the logic board due to a missing part, the battery charger will assume that too much current is being drawn and therefore, will shut off the battery charging mosfet @ Q7055.

Measure and post the readings for the points # 1, #2 and # 3.

Thanks a bunch for the quick reply mon2!
Did a quick measurement of the battery connector. A bit too tired to do the full disassembly today.
Will try tomorrow.

Pins at power off state with charger connected.
Black probe at chassis.

J6950:
1-3 10.93V
4 3.4V then fluctuating down to about 2V?, then 3,4 again.
5 0V
6 3.4V then fluctuating down to about 2V?, then 3,4 again.
7-9 0V as expected.

[trondl]

Re: MacBook Pro 2010 15" 820-2850 no charge, green light, powers on

Hi again!
Finally had the time.
Here's the remaining results (Negative probe on shield):

1. PPBUS_G3H measured on both sides of F7040 (not blown/open):
10.92
2. PPVBAT_G3H_CHG_R measured on positive side of C7055:
10.92
3. PPVBAT_G3H_CONN meassured on Q7055 pin 5 (Q7055 itself showed no shorts between D, G & S in diode mode and no power. ~0.5Vdrop):
10.92

10.92 seems to be quite the repeating number here, same I found on pins 1-3 on the battery connector.
One thing I noticed: when I did run the board bare naked (also without the fans for some silly reason), there was no LED colour on the charge plug.

Also, I measured the DCIN board: 16.7V, again with shield as ref.

[mon2]

Re: MacBook Pro 2010 15" 820-2850 no charge, green light, powers on

If there is no light on the magsafe power head, then there is no voltage to power the single wire communication of the Dallas / Maxim controller. This controller is chatting with the logic board and is used to select the bicolor led inside the power head.

Check the 3v42 or 3v3 line for your board..it should be powered by a dual common cathode diode. Fed by ppbus_g3h and the adapter voltage.

Locate it and post the voltage on this diode to start.

[trondl]

Re: MacBook Pro 2010 15" 820-2850 no charge, green light, powers on

Sorry, scratch my last posting.
The board wasn't starting without the fans installed.
Got green led and fan spin now.
Correct values:

1. F7040 12.63
2. C7055 12.63
3. Q7055 10.92

Also I think I found the double diode you mentioned, although it seems to be a Vreg: VR5020 ?
Pin 2 (PP3V3_S5_AVREF_SMC):
3.32
Pin 1 (PP3V42_G3H):
3.42

Or is it D7005 near U7000 you meant?
1 PPDCIN_G3H
2 PPDCIN_G3H
3 CHGR_DCIN_D_R

Haven't probed there yet.

[mon2]

Re: MacBook Pro 2010 15" 820-2850 no charge, green light, powers on

The voltage readings look ok. Green light is a good sign.

You have a 'fresh' battery installed and the magsafe does not ever go orange to denote charging ?

Does the macbook report the presence of the battery ? Can you dump the details of the battery in the information page ?

[trondl]

Re: MacBook Pro 2010 15" 820-2850 no charge, green light, powers on

I have two fresh 3rd party (subtel brand) batteries and the old one that did actually charge and gave orange but couldn’t stay on it’s own.
Also, coconutBattery claimed that the current capacity on the old one was slightly above spec when fully loaded.
May the veeeery slow charge time on the old battery be a hint at something about to fail?
I’m also tempted to see if the old battery can still charge, but since it is almost fully charged, I probably won’t be able to.
A safe way to discharge the old one without risking fire?

The stats for the new batteries where normal in macos, battery installed but not charging.
Can run on it’s own ang gave all details in coconutBattery, except a weird serial#.

[mon2]

Re: MacBook Pro 2010 15" 820-2850 no charge, green light, powers on

A safe way to discharge the old one without risking fire?

Yes - run Youtube videos all day till it discharges normally while on battery power.

Do confirm if the original / older battery can charge on this logic board.

This will validate the charging circuit is ok.

[trondl]

Re: MacBook Pro 2010 15" 820-2850 no charge, green light, powers on

Yes - run Youtube videos all day till it discharges normally while on battery power.

Do confirm if the original / older battery can charge on this logic board.

This will validate the charging circuit is ok.

The major issue is that the old battery won't run on it's own.
The board dies immideatly without magsafe.

Btw: where are the current sense resistors in the circuit?

I have a hunch this machine has only sat in an office all day with magsafe 24/7.

[mon2]

Re: MacBook Pro 2010 15" 820-2850 no charge, green light, powers on

The old battery is then depleted..it is unable to hold its charge.

See attached. Current sense for the battery charge leg of the circuit = R7050.

It is vital that the same resistance is read from each side of R7050. Confirm that you have these connections back to the ISL charger IC.

Have seen a case where the PCB trace was broken and had the same symptoms.

Have to wolf down a late breakfast and then fix some blinds (they are not the LG brand) - BBL.

[trondl]

Re: MacBook Pro 2010 15" 820-2850 no charge, green light, powers on

Traces back via R7050, R7051/R7052, C7050 and at U7000 look good.
There is about 3.1ohms over C7050.
R7050 has about <2ohm according to my non-Fluke dmm.

[trondl]

Re: MacBook Pro 2010 15" 820-2850 no charge, green light, powers on

Can verify that the old battery won’t charge either.
Starting to look like a bad ISL?
Not much experience with hot air yet, but have plenty of junk boards to dry run on.
Or could this actually be smc related?
I did after all feel a tingle when installing the first battery.

[mon2]

Re: MacBook Pro 2010 15" 820-2850 no charge, green light, powers on

Perhaps. See attached.

With great care, measure the voltage on each point of interest.

We want to know if the high and low side mosfets are working to charge the battery. You can measure where you feel comfortable - if the probes are not suitable, just hold off and can try other measurements.

With the adapter and battery connected, you should see the presence of a charge voltage at the drain pins of mosfet Q7055 (pin # 5-6-7-8).

What is the voltage you measure at the drain pins of Q7055 ?

What voltage do you measure at the GATE pin # 4 of Q7055 ?

This is to confirm that the ISL charger IC is attempting to charge the battery pack - the batteries being dead is another story.

Have to go trim my weeds to keep up with the Jones' and to beat the rain - bbl.

[trondl]

Re: MacBook Pro 2010 15" 820-2850 no charge, green light, powers on

Your attachment asks for Q7030 and Q7035.
Q7055 has been measured earlier as I understand it.
All ref to shield.

Q7030
S 12.56V
G 16.12V
D 16.6V

Q7035
G 0.96V

[mon2]

Re: MacBook Pro 2010 15" 820-2850 no charge, green light, powers on

Q7030
S 12.56V

Can you confirm this is the voltage that you see @ fuse F7040, pin #1 ? It should be.

Respectively, confirm this same voltage should be @ Q7055, source pins 1-2-3. It should be the same.

Yet, Q7055, drain pins (5-6-7-8) are at 10v92 (from an earlier post)? Something wrong here. Either this mosfet is disabled or defective if the gate voltage is high enough. This is the raw battery voltage.

Confirm the voltage on mosfet Q7055, gate pin # 4 so we can verify that it is enabled.

[trondl]

Re: MacBook Pro 2010 15" 820-2850 no charge, green light, powers on

I measured 12.63 on both sides of the F7040 fuse earlier.
Q7055 did have raw battery voltage at drain, yes.
I’ll do a proper measurement of q7055 tomorrow after work.

I must again say thanks a bunch for the knowledge and will to help me out here!

[mon2]

Re: MacBook Pro 2010 15" 820-2850 no charge, green light, powers on

No worries. Hope it is for the best. Then one day, we can visit Odda with a Thor hammer and throw it a pile of these macbooks for practice.

[trondl]

Re: MacBook Pro 2010 15" 820-2850 no charge, green light, powers on

No worries. Hope it is for the best. Then one day, we can visit Odda with a Thor hammer and throw it a pile of these macbooks for practice.

Then celebrate with at least a bathtub of mjød (mead)!

I believe we have a smoking gun:

Q7055:
Gate 12.57V, which should according to my humble experience be more than enough to turn it on?

Sink 12.64V and Drain 10.92V for completion.

[mon2]

Re: MacBook Pro 2010 15" 820-2850 no charge, green light, powers on

My bad...Q7055 = P-channel mosfet.

https://www.vishay.com/en/product/69063/

So the GATE is required to be lower (negative) than the voltage it is passing.

With the GATE @ Q7055 being so high (~12v), the mosfet is being requested to remain OFF.

Remove all power / remove the battery.

Measure the resistance across Q7055 legs (aka battery mosfet).

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

bathtub of mjød (mead)!

LOL. Love the Ragnarok (Netflix) series...cannot wait for the final season to start. Have not watched the films yet.