Macbook Pro A1706 not turning on with battery

[mferna14]

Hi., today working on a Apple MacBook Macbook Pro A1706 (Board part # 820-00239-A) not turning ON with battery. The notebook turns on 100% fine with USB-C Power adapter (NO BATTERY INSTALLED), boots up well & all seems to be perfect. I connect J6950 to the main battery terminal & it's fine, boots up well but does not work with battery as till now the MB did not detect the battery & no battery icon shows up. As soon as I connect the BDM battery flex cable to J6951, the ampmeter display goes on & off & takes only 5v & this is in a loop (display comes & goes after detecting 5v, on & off) till the BDM flex cable is attached & MB does not turn on. Once I take out the cable from J6951, all works fine again. Without this BDM flex cable the voltage on Q7065 Drain (pin 5) is 11.5V . Kindly need some help in this, if someone could guide me. Thanks in advance.

[mferna14]

Re: Macbook Pro A1706 not turning on with battery

Forgot to add the pin voltages on J6951:
Pin 1 0V
Pin 2 3.4V
Pin 3 3.4V
Pin 4 0V
Pin 5 0V
Pin 6 0v

[mon2]

Re: Macbook Pro A1706 not turning on with battery

Hey The voltage on the battery mosfet is suitable to charge the battery so the charger side at this time looks good. Concern is with the battery itself. Is there a charge on the battery? Check it out of circuit. Suggest to buy a known good battery from Amazon for testing. The bms on the battery pack may be defective.

Here at the Mobile Electronics fair in HK and somewhat disappointed with the tech vendors. Lots of power adapter, iPhone LCDs and only a few with repair parts for the above. A few claim to supply others but imposing large MOQ. Most are from Shenzhen. More details after a last day visit to the fair.

[mferna14]

Re: Macbook Pro A1706 not turning on with battery

Thank mon2., I put in a brand new battery right now. Do you think the new battery is defective??? Is shows 0V on the position terminal. I think there might be a battery sense, then it might turn on... Do you think this battery is similar MacBook Air A1466 battery, when checked, it always show volts above 10V or in other words it should alway be in ON status & give voltages.

[mon2]

Re: Macbook Pro A1706 not turning on with battery

Does the battery show a charge when it is out of circuit? Can the pre-charged battery power the laptop without the power adapter ? If not sounds like a leaky mosfet which should be checked. Start with the battery mosfet with no power. Check the resistance across the mosfet.

The same battery pack is known good and works with others of the same model?

[mferna14]

Re: Macbook Pro A1706 not turning on with battery

mon2., the new battery only shows .78v when out of the logic board/casing on the two battery terminals & it does not power on the laptop, this I checked with no USB-C power into the laptop. Surely I will check the MOSFET & inform you. I do not have any other model A1706 like this one & this is why could not check the new battery & match any voltages. I was checking another laptop MacBook Pro A2159 battery, stand alone, it shows 12.8V on the main battery terminals. I think some MacBook models do not have a battery turn on pin!! & these 2 terminal have AON voltages on the terminals.

[mferna14]

Re: Macbook Pro A1706 not turning on with battery

mon2., today I got another new battery & all worked fine. Problem was that I purchased a "so called new battery" for a local vendor & it was defective (I mean selling defective battery), this is why I was having problem with the battery section. This time I ordered from Amazon & a good quality one & all is working fine, no problems at all & charges well too. Thanks for the help.