Apple Macbook Pro Mid-2014 A1398 - Battery detection FAIL

[rigway]

Hi Everyone!

Will be forever grateful if someone can give insight/direction.

Got machine with liquid damage - Apple MacBook Pro 15-Inch "Core i7" 2.5 Mid-2014 (DG). Wasn't powering on completely. After inspection got the idea that charging IC is blows and couple more places of corrosion (swapped few more components form doner board).

I have a spare working logic board with irrelevant physical damage (just a donor board to me now) Apple MacBook Pro 15-Inch Mid-2014 (IG).

Replaced U7100 (ISL 6259) from it - powers on OK now, though battery is not getting detected. Battery is tested and is good working one, tried it on another machine. Eventually just to be sure bought a NEW chip from eBay - replaced again - same thing - no battery detected in OS, nor does it charge or powers off it.

MBP however boots OK and works of the charger. Shame to be wasted.. Any advice possible what to check? Got stuck as I'm not quite sure where to look next in terms of troubleshooting but want to use this opportunity to get more out of this rather than just a fixed laptop.

Tested it with ASD. Reports a bad sensor..
Sensor Group (test #7) - SensorGroupLimits.prm

Thanks,

Jay

[mon2]

Re: Apple Macbook Pro Mid-2014 A1398 - Battery detection FAIL

Hi. Not in front of my schematic database but check...

1) battery mosfet to review the voltages on each pin of source, gate, drain. If the logic board fails to work off battery, this is a good place to start. Then remove all power and check the resistance of this mosfet:

Source & drain
Source & gate
Gate & drain

Looking for a low resistance which denotes a damaged part and needs to be replaced.

2) the logic board knows if the battery is present by pinging the battery using the I2C (smbus) lines (sda & SCL). Remove all power. Meter in resistance mode (2k scale). In resistance mode, check the resistance to ground of these lines. Then when powered by the adapter and with battery connected, use meter to check the voltage of these I2C pins. Post the readings.

If the voltage is ~3v3 for each then this is a good value.

[rigway]

Re: Apple Macbook Pro Mid-2014 A1398 - Battery detection FAIL

Hi,

I'm getting stuck with this board. Was cleaning off some corrosion next to SMC. All traces are good, however it's not powering on at all. Back to more major issues now.

Was following guide on:
https://repair.wiki/w/A1398_2013-201...ook_Pro_Retina
Checking all possible causes and currently have the following situation.

When plugged in with a known 85W MagSage 2 Adapter with everything disconnected:
PPBUS_G3H on F7140 = 0.4v
PPBUS_G3H on R7005 = 0.4v
No green light

I guess I've messed up something..

[mon2]

Re: Apple Macbook Pro Mid-2014 A1398 - Battery detection FAIL

Remove all power.

Meter in resistance mode (2k scale or similar).

Check the resistance to ground of F7140.

Post the resistance.

[rigway]

Re: Apple Macbook Pro Mid-2014 A1398 - Battery detection FAIL

Hi mon2,

Thanks for checking my 'progress' from time to time Honestly appreciate it. Been busy with fixing car.

Right, I got frustrated with this MBP to say the least Few days ago I realised that accidently knocked off one little bit next to charging chip (ISL625), which I tried to reseat once again as I thought maybe there was an issue with it. At this stage have two working ones. Got it sorted, than have put missing bit next to it from donor board.

Situation now:
When MagSafe 2 gets attached only from cold boot light goes to Orange than it starts to fade away slowly until completely off, no fan spin tho. Consequent reattachment of MagSafe 2 power just leads to nothing. Checked resistance as you suggested on F7140 after all that with everything disconnected and it's 1.579. Does that mean that there is a 'leak' to ground now?

Reason why I wanted to get this board working rather than my donor board is that it has a dedicated GPU chip, however this donor board had a ripped iSight connector and pads ruined. Got it from someone in this state, don't ask

After realising that I'm getting stuck with my prefered board I've moved stuff to that i7 only logic board (my donor). Did some microsurgery as decided to attempt to move iSight connector to that donor board. It's a booting/posting board. Just waiting for a heatsink to fully test it..

Just to summarise:
I still want to fix that initial board, will be getting more donors for bits and another iSight connector. Luckily desoldered it with no issues. Based on my resistance test - what is best to check further on it? (when I'll get new bits)

Many thanks in advance for your help!

[mon2]

Re: Apple Macbook Pro Mid-2014 A1398 - Battery detection FAIL

Great pics. The meter shows a 'M' in the measurement so your resistance to ground is 1.579 mega-ohms = 1,579,000 ohms. That is, you definitely do not have a shorted capacitor on this power rail. This is good.

Next, use the same resistance mode to check if the fuse F7140 is blown or not. Remove all power and check the resistance of the fuse.

If the fuse is ~0 ohms, the fuse is good. Confirm it.

If the fuse is blown, check the voltage on the other pin of this fuse.

If the fuse is NOT blown, then remove the fuse (with of course all power removed).

Then power on and check the voltage on the F7140 fuse pad that is towards the ISL charger IC.

Post the measurement of the voltage.

This charger IC could be defective or is not enabled but need to do more testing to confirm.

[rigway]

Re: Apple Macbook Pro Mid-2014 A1398 - Battery detection FAIL

Having fun now with that 'donor' board now ; )) in a bad way.

Decided to open another thread for it, otherwise it will be a mix of two separate repairs, which I guess is no good for anyone to follow.
https://www.badcaps.net/forum/showth...05#post1120705

Will be getting back to this one in this thread after I will get another donor eventually.