⟐ Answered February 13, 2026 at 17:48 MST

⟐ Answer accepted January 30, 2026 at 20:00 MST

⟐ Answered January 29, 2026 at 5:36 MST

⟐ Commented January 26, 2026 at 15:00 MST

Added a new battery today and not Good so far.

The device only powers on with power cable connected.

It won't turn on straight away when I press the power button, if takes a minute or so then comes on.

When I originally put the trackpad back and notice a spark, would this device be shot here even of its turning on at the moment?

I've also just ordered another BMC flex cable.

Help appreciated

Here you go on images

UPDATE - Just noticed I didn't unclip the BMU when removing.

Also, the connector to the battery board came out when installing.

1. Could these be broken if yanked out not pulled out with the clip open?

2. Does a new cable solve this? If yes I'll need to wait a few days till it arrives to conclude on this!

3. My god Apple complicate things on mainboards lol. You need to be Tom Thumb

Update - just tried multimeter on new battery and got readings so suggests it isn't a dud battery?

⟐ Commented January 26, 2026 at 5:58 MST

⟐ Answered January 25, 2026 at 20:26 MST

I've got the laptop from a friend that said that he spilled some coffee on it. Currently the device won't turn on not matter what I've tried.

I've opened the backpanel and saw that the track flex connector seems a little burnt and the ZIF connector on the board itself seem to be broken.

I've tried to turn the device on while the trackpad is disconnected without any luck.

My question is, could that prevent the device from turning on? Or there might other issue be causing that?

Thanks.

⟐ Commented December 28, 2025 at 1:44 MST

⟐ Answered December 05, 2025 at 16:59 MST

⟐ Commented December 03, 2025 at 16:30 MST

I have a very strange issue on the macbook

Issue is

Charger gets plugged in with am-meter and it shows 5V>20V and 1.5A on battery and approx 0.6A when the battery is disconnected.

PPBUS_G3H is present on F7000 on both sides and when in Ohms mode readings are expected

Nothing is shown on external monitor and caps lock key doesnt light up

The CPU gets very hot,.

Any advice please

⟐ Answer edited December 03, 2025 at 7:48 MST

⟐ Answer edited November 30, 2025 at 16:37 MST

I have a 2017 Macbook Pro 13” function keys. Almost 3 weeks ago, I was using my laptop then all of a sudden the keyboard and trackpad stopped working. Even during boot, it does not recognize either of them. I cannot run SMC reset or anything. It is currently stuck in recovery mode telling me to turn on my mouse or trackpad since the internal device is not detected. I tried connecting a mouse and keyboard and the mouse worked fine, but I think the keyboard I was using was acting funny. I am going to try and get a hold of an Apple Keyboard and Trackpad or Mouse and see what I can figure out with an SMC reset and Apple Diag.

I took it to an Apple Store about two weeks ago, they took it to the back for 10-20 minutes, and couldn’t get anything to work. They didn’t give me many details on what they did, other than checking the connections and reseating them. They quoted me almost $500 to get it fixed because they were unsure if it was the trackpad and keyboard or logic board, but for double that I could buy a new laptop, so of course, I walked out.

I work on computers for a living, so obviously I’m fine with working on these, I was just seeing if I could get some free diag from Apple, but nope. Has anyone had a similar issue? I plan on running these commands tonight, hopefully, to see what I can come up with. I will post the results.

Thanks in advance,

Austin D.

⟐ Commented October 19, 2025 at 4:46 MST

⟐ Answer edited October 13, 2025 at 6:13 MST

If I don't have the charger plugged in and the computer is switched off, the 'battery needs charging symbol appears' and that's the only time the battery is acknowledged as being present.

If I plug out the battery data/daughter cable from the logic board and try to turn on the PC that symbol no longer appears and there is no power in the system so it must be detecting the battery to some extent. I have also tried doing SMC and PRAM resets multiple times. Is there any other suggestions? Thanks.

-- Update

CoconutBattery shows the following information:

The cable connection:

⟐ Answered August 19, 2025 at 8:16 MST

I'm facing a backlight issue due to liquid damage on a macbook and I'm wondering if someone can help me .

My board is a A1708 820-0080-A

I already have few information after few measurement .

I'm not an expert on this but have few electronical notion .So I'm sorry if I cannot understand all specifical technical terms of your answers .

First below few things to confirm my issue :

• I have image but no backlight
• I can use the laptop but with an external screen
• When I opened the macbook the fuse was cutted
• few corroded area but not dramatical .
• I've cleaned everything to remove all those corroded area with a very soft brush and iso alcohol
• I think the caps are good after measurement with a multimeter . I found almost the sum of the capaticance value on the schematic . (probably not the right way but )
• In continuity mode with LCD connected (J8500) , the output line PPVOUT_SO_LCDBKLT is shorted to ground .It's the same when the backlight connector J0803 is disconnected .

* And last there is no shorting when the LCD is disconnected (J8500) .

• When I tried to measure for shorting on the J0803 connector (backlight) which is on the additional PCB attached to the screen with LCD completely disconnected to the main board , I found shortage between PPVOUT_SO_LCDBKLT and ground on the this connector which was also corroded . I guess this is the issue .
• Doest someone know if I can buy this connector somewhere ? or the name of this connector ? Is that an FPC type ?

*

• I've solder back a new fuse and measured 0.002v in the output line PPVOUT_SO_LCDBKLT.
• I also measured voltage on the first mosfet with is the Q8400 and the gate voltage which is 12v so it isn't the one expected around 5.2v as on the attached picture .

*

My understanding is the following : the backlight IC doesn't short the R8402 to GND so the voltage divider is'nt working properly . Why I don't know . Bad driver or due to the shorted output the driver doesn't allow the SD line to be grounded .

I hope someone can help me .

Thanks in advance for you time and help .

UPDATE 12/04/2023 : I removed the J0803 connector and still have the shorting . Which means that there is another circuit linked to the backlight on the T-CON board .

@littlegreenrock You were right something in going on where you pointed .

@flannelist you were also right , something is going on below the shield . But not easy to remove ..... I'll try anyway even if just for curiosity .

Right now I got a broken screen but good T-CON board .. I don't know if I'll be able to switch some components in order to repair the good one .
It's unfortunate because I know the LCD pannel is good and the backlight is also good .....

I'll probably have to change the whole screen .... :'(

I'll let you all know when I have some news

Update 18-05-2023

Hi everyone ,

I tested a working screen at least the backlight on my macbook and still no backlight . No short measured on the backlight output when the screen is connected via LVDS compared to before . So first good news .

Still no working backlight although which means that i have an issue on the MB .

I replaced the U8400 but no change . I still have the gate voltage issue which is not grounded so the same as the source (13v on pin 3 & 4) .

There is a lot of test point around this IC . And I want to test them in diode mode .

Does someone here have the value that I should get on those points please ?

Thanks for your help .

Hi everyone, little update.

I forced the R8402 pin 2 to be grounded and I get 12v at en backlight circuit output . Now I have 5.7v on the gate as it supposed to be . But no 44v for the moment .

Which means I have probably issue with the second Mosfet which boost the voltage . Does anybody knows how this second one works?

Ont question aswell , what's the meaning of those two signals ?

-TCON_BKLT_PWM

-EDP_BKLT_PWM

I read that if PWM signals is 0 . The backlight circuit will remains off . Some of the repair shop force that PWM signals to be a 3.3v which correpspond to 100% . If that's the solution I will go for it but in your opinion where to I have to inject the 3.3v ?

Thanks in advance.

⟐ Answer accepted August 05, 2025 at 2:09 MST

⟐ Answer accepted July 29, 2025 at 4:06 MST

I have a MacBook Pro (13-inch, 2016, 2 TBT3) purchased in April 2017. Its hard drive is not getting recognised during booting.

Have tried various options to boot the Macbook viz. using

• DiskUtility. Booting using Option+Command+R etc.
• Installed MacOS Monterrey - thinking its a good old stable version for this old Mac - on a USB drive and used the USB drive to boot the Macbook. It only shows the External USB Drive but not the Internal HDD.
• Installed Linux on the USB drive like above but the result was same.
• Used a thunderbolt cable to connect to a working Macbook. Though, I bought this cable on eBay and not on Apple store but has the thunderbolt symbol and looks genuine. After connecting, the non-working Macbook shows a thunderbolt symbol on the screen but on the working Macbook Finder, no sign of the HDD as an external drive in Location

Hoping its not a hardware failure but possibly a firmware issue. And hoping against hope that I will able to recover the data on it.

When the last time I was successfully able to boot the Macbook, the HDD was very close to being full.

Any guidance and help to resolve this issue is much appreciated.

Thank you very much.

⟐ Answered July 07, 2025 at 4:41 MST

I’ve already tried SMC and NVRAM resets with no improvement.

When I disconnect the external display and attempt to run Apple Diagnostics, the built-in screen shows the Apple logo (only visible with a flashlight), but it freezes there and diagnostics never begin.

Does anyone know how to successfully run diagnostics in this situation, or at least identify the hardware issue? Local repairs are extremely expensive, so any tips, workarounds, or experience would be greatly appreciated.

⟐ Commented July 05, 2025 at 9:30 MST

hi all, update here, Apple Store did not diagnose it more. I got it back, removed the SSD to try and see if I get something else. Unfortunately no, still stuck on Apple logo nothing else happens. It should give a question mark right now not? So if it's not showing the question mark probably something else is broken? Any ideas what to do next?

⟐ Commented July 04, 2025 at 14:54 MST

I’m having some troubles with my 2017 non-touchbar macbook pro. The macbook works operates fine but once I close the lid, I can’t wake the computer unless I reset the SMC holding CTRL-Option-Shift-Power. As long as I don’t close the lid, I can sleep from the power menu and wake it by pressing any button the keyboard. I’m thinking it’s a problem with the lid sensor. This obviously gets very annoying since I cannot close the lid without having to completely reset the smc and reboot every time. Could anyone help me out?

⟐ Commented June 30, 2025 at 19:17 MST