After Changing Battery - Mid 2015 Macbook Pro Trackpad & Keyboard Not Detected?

Suave! wrote:

Hi All,

I have a mid 2015 A1398 15" rMBP. It needed a new battery

I very carefully removed the existing battery & installed the new one. Upon starting the rMBP with the new battery, I got a message stating the the Keyboard & Trackpad was not detected & neither of them responded to any input.

Apple Diagnostics—

"Battery Needs Service" - code: PPT004

NDR001 a corrupted Trackpad

?

PPT004 —

NDR001 —

You say nothing about where these do-it-yourself parts came from....(?)

If you do not do these type repairs day in and day out, these connectors are easily damaged both removing & reinstalling...

Any computer repair shop that works on Macs— can sort/guarantee a repair, sounds like you could use the help there.

.

You are assuming the replacement Trackpad and Trackpad IPD Flex Cable are good. The Trackpad flex cable does have an extremely high rate of failure for the 2015 model, so that would be my first guess. There is also a chance either the Keyboard Cable or even the Logic Board was accidentally damaged (the Logic Board is more likely of the two).

Unfortunately there is no way to know for sure except to test with a known good Trackpad flex cable, then a known good Trackpad. The Trackpad Cable is the most likely part to fail and is also the least expensive & easiest to replace.

As for the third party battery failing the Apple Diagnostics, this is not unusual. Some third party batteries will provide a proper response to the diagnostic queries, while others will not. In fact one third party battery I just installed failed the Apple Diagnostic the first time, but passed when run a second time a few minutes later. The quality of third party Lithium batteries is unfortunately extremely poor even when purchased from a reputable vendor.

Any third party batteries that are considered identical to the OEM, may possibly be batteries made for Apple, but did not pass the stringent tests for Apple, so they were sold on the third party market instead. If these batteries were not good enough for Apple, then of course they likely have some sort of issue...maybe something that most will find acceptable, or some may have potentially have an issue which will cause the battery to degrade more quickly. All I know from personal experience with Lithium batteries for nearly 20 years....it is extremely hard to find a good quality third party Lithium battery.....even if you find an excellent one today, the next time you order one from the same place it may be completely different quality.

Suave! wrote:

The fact that at one point, after doing a PRAM reset via an external keyboard allowed the Cursor, Trackpad & Keyboard all to become fully responsive gives me hope that this might be some sort of software/OS Glitch as I read many others also had non responsive Keyboards/Trackpads in the past simply by updating their operating systems? 

With the above in mind, any further ideas now how to now resolve assuming that there is no hardware, cable, connector damage etc?

A PRAM Reset just clears out the Non-Volatile RAM (NVRAM or PRAM....Parameter RAM). So the OS is very unlikely to be the problem here unless it is somehow corrupting or configuring the PRAM improperly. However, since this issue only started after the battery replacement, it seems highly probable that something was accidentally damaged.

With this specific 2015 model laptop, the Trackpad IPD Flex Cable has an extremely high rate of failure due to how it is routed over top of the battery. The older Retina laptops routed this cable beneath the battery where it would not get worn or damaged. Because the Trackpad Cable has such a high rate of failure for this particular model laptop, and because the cable is the least expensive & easiest part to replace, it just makes sense this should be the part to try again especially since you acquired a used cable.

Unfortunately it is impossible to say which piece of hardware is at fault here since I have seen the Trackpad Cable cause intermittent issues just like you have described here. It is also unlikely you will be able to detect any flaws in the cable through a visual inspection. Sometimes rebooting or resetting the PRAM will "fix" it for a little while, so anymore I will always replace the Trackpad Cable without question.

When I've had the built-in Keyboard & Trackpad fail at the same time, it could be anyone of these three parts.....Trackpad Cable, Trackpad, or Logic Board. Of these parts, the Trackpad Cable is the most likely especially if you are not installing a brand new cable. I've had to replace the Trackpad on one or two laptops and maybe one Logic Board to fix this type of issue. I've replaced many more Trackpad Cables on this model for our organization than these other two parts combined. Everything else being equal, the odds favor the cable being faulty.

Reinstall you OS maybe?