SOLVED Keyboard Issues - Ghost Scrolling - Can't Reset PRAM

[Larry767]

I have a Mid-2015 15" Retina MacBook Pro. The user complaint was something to the effect of the "trackpad is behaving weird". Based on that I suspected maybe it was a swelled battery issue or faulty trackpad which I have seen before. But it is none of those. Battery is fine and trackpad works. I might need to post a video to show you what this is doing but I'll try to explain it first.

If I open Safari and start to type in the search bar, all is good unless I start with an "o" or an "L" in the first few letters. As you type, a drop down list appears with autofilled "suggestions". When I get to an "O" or an "L" it starts scrolling rapidly up and down the list, almost as if someone is pressing the down cursor key. I have also discovered that while this is going on, if I mouse up to the menu bar and click on the Apple menu (or File or any of them), the cursor will start cycling down through all the menu items. I think if I press ESC it stops momentarily but that's it.

Here's what I've tried (none have made any difference).

1. Open up Notepad or TextEdit and type. All keys type as they should.
2. Reset the SMC - this appears to work. Light on charger goes from orange to green and back to orange again. Good, but no difference.
3. Reset the PRAM - For some reason, I am unable to do this. When I power on the MacBook it seems to take a ridiculously SHORT amount of time for the Apple logo to appear. On other machines I've done this on there is usually a couple second delay between the startup chime and the Apple Logo - not with this machine. It chimes and then under 1 second later the Apple logo appears. I also tried just holding option to boot from another device - NOPE. I can't even hold D or R or cmd-d or cmd-r to boot to recovery mode. No matter what I try it just immediately starts to boot. I even tried swapping out the SSD with another one with fresh macOS on it and it does EXACTLY the same thing. I also tried sudo nvram -c in terminal but if that does the same thing as cmd-opt-P-R then that did not fix the problem.
4. Tried a USB keyboard - NOPE, same behavior.
5. Opened the Mac and disconnected the keyboard, inspected it for corrosion, and reinstalled it. - NOPE same behavior.

What can I try next? I'm out of ideas? It especially concerns me that I can't zap the PRAM on this machine. Is there a way to block this in firmware that I'm not aware of? And if so, how do I unblock it?

 

[TonyAguila]

I have a Mid-2015 15" Retina MacBook Pro. The user complaint was something to the effect of the "trackpad is behaving weird". Based on that I suspected maybe it was a swelled battery issue or faulty trackpad which I have seen before. But it is none of those. Battery is fine and trackpad works. I might need to post a video to show you what this is doing but I'll try to explain it first.

If I open Safari and start to type in the search bar, all is good unless I start with an "o" or an "L" in the first few letters. As you type, a drop down list appears with autofilled "suggestions". When I get to an "O" or an "L" it starts scrolling rapidly up and down the list, almost as if someone is pressing the down cursor key. I have also discovered that while this is going on, if I mouse up to the menu bar and click on the Apple menu (or File or any of them), the cursor will start cycling down through all the menu items. I think if I press ESC it stops momentarily but that's it.

Here's what I've tried (none have made any difference).

1. Open up Notepad or TextEdit and type. All keys type as they should.
2. Reset the SMC - this appears to work. Light on charger goes from orange to green and back to orange again. Good, but no difference.
3. Reset the PRAM - For some reason, I am unable to do this. When I power on the MacBook it seems to take a ridiculously SHORT amount of time for the Apple logo to appear. On other machines I've done this on there is usually a couple second delay between the startup chime and the Apple Logo - not with this machine. It chimes and then under 1 second later the Apple logo appears. I also tried just holding option to boot from another device - NOPE. I can't even hold D or R or cmd-d or cmd-r to boot to recovery mode. No matter what I try it just immediately starts to boot. I even tried swapping out the SSD with another one with fresh macOS on it and it does EXACTLY the same thing. I also tried sudo nvram -c in terminal but if that does the same thing as cmd-opt-P-R then that did not fix the problem.
4. Tried a USB keyboard - NOPE, same behavior.
5. Opened the Mac and disconnected the keyboard, inspected it for corrosion, and reinstalled it. - NOPE same behavior.

What can I try next? I'm out of ideas? It especially concerns me that I can't zap the PRAM on this machine. Is there a way to block this in firmware that I'm not aware of? And if so, how do I unblock it?

I would try reinstalling macOS. That MacBook Pro model can run macOS 12 Monterey (12.6.8, I think). It’s usually one of the first things I try whenever “weird” behavior starts happening on the Mac. Also, keep in mind that whenever you perform a PRAM reset, TRIM will become disabled and you will need to do a forced reset to prevent damage to your SSD(s). If, afterwards, you still feel a need to reset parameter RAM and the keyboard method still doesn’t work, I can show you how to do it via Terminal.

 

[MacsBug]

The popup list is a feature of macOS if you were to hit the F5 key after you type a few letters. See if there is any macro or keyboard remapping software installed


If this is not a software issue, before reinstalling your OS, there are a couple of things to try to see if its hardware related,

1. Boot the MacBook Pro in safe mode. You can do this by holding down the Shift keyas soon as you hit the power button and keep on holding it down thoughout the boot process. You will see Safe Boot on the right side of the menubar if you successfully booted in Safe Mode.

2. Try booting from an external drive.

In both of these scenarios see if you can reproduce the issue, If it persists on both of these, then you may need to replace the keyboard.

 

[TonyAguila]

The popup list is a feature of macOS if you were to hit the F5 key after you type a few letters. See if there is any macro or keyboard remapping software installed


If this is not a software issue, before reinstalling your OS, there are a couple of things to try to see if its hardware related,

1. Boot the MacBook Pro in safe mode. You can do this by holding down the Shift keyas soon as you hit the power button and keep on holding it down thoughout the boot process. You will see Safe Boot on the right side of the menubar if you successfully booted in Safe Mode.

2. Try booting from an external drive.

In both of these scenarios see if you can reproduce the issue, If it persists on both of these, then you may need to replace the keyboard.

Or if it is a hardware-related issue with the keyboard, you might be able to check how it works with an external USB keyboard first.

 

[Larry767]

The popup list is a feature of macOS if you were to hit the F5 key after you type a few letters. See if there is any macro or keyboard remapping software installed


If this is not a software issue, before reinstalling your OS, there are a couple of things to try to see if its hardware related,

1. Boot the MacBook Pro in safe mode. You can do this by holding down the Shift keyas soon as you hit the power button and keep on holding it down thoughout the boot process. You will see Safe Boot on the right side of the menubar if you successfully booted in Safe Mode.

2. Try booting from an external drive.

In both of these scenarios see if you can reproduce the issue, If it persists on both of these, then you may need to replace the keyboard.

1. It seems like NONE of the startup keys work, including Shift - I am not able to get it to boot to safe mode.
2. I can't hold option and select an external drive so that's out. I did swap out the internal SSD with another one that had a completely different macOS on it. Same behaviour - so I think I can rule out software.

Note: I tried disconnecting the trackpad. It seemed to disable the keyboard as well but I used a USB keyboard and found that the behavior described did NOT occur. It still chimes and displays the Apple logo simultaneously, not allowing enough time for me to activate a modified startup but typing O or L in the Safari url bar no longer activates scrolling. So I thought maybe I need to replace the trackpad assembly? Just the cable? I ordered a new trackpad and cable but neither of those solutions made any difference. Still starts scrolling when I press o or l and I can't activate any startup keys to reset PRAM, boot to recovery, Option boot to an external drive, safe mode, etc.

Can anyone tell me why the keyboard is disabled when you disconnect the trackpad? Still bothers me that there is no delay between chime and apple logo making it impossible to reset the PRAM or boot from recovery or select a different startup volume. I also swapped out the internal SSD for another with completely different os. Same behavior - starts scrolling down as soon as I press the o or l keys. Do I replace the top case?

 

[Larry767]

Or if it is a hardware-related issue with the keyboard, you might be able to check how it works with an external USB keyboard first.

USB keyboard does the same thing. Pressing o or l triggers the scrolling, same as with the built-in keyboard.

 

[Larry767]

I would try reinstalling macOS. That MacBook Pro model can run macOS 12 Monterey (12.6.8, I think). It’s usually one of the first things I try whenever “weird” behavior starts happening on the Mac. Also, keep in mind that whenever you perform a PRAM reset, TRIM will become disabled and you will need to do a forced reset to prevent damage to your SSD(s). If, afterwards, you still feel a need to reset parameter RAM and the keyboard method still doesn’t work, I can show you how to do it via Terminal.

Did that. Also tried swapping out the SSD for one with a totally different macOS. No difference, same scrolling when I click o or I. I did try to reset the PRAM through terminal using instructions found online but it didn't seem to do anything. Note that even with no SSD installed the Apple menu appears instantaneously with the chime and stays on for about a minute before finally displaying the flashing question mark.

 

[Larry767]

UPDATE: I tried once more to disconnect the internal keyboard and connecting a USB keyboard and the scrolling issue seemed to go away - and I was able to OPTION-Boot and boot to diagnostic mode with the USB keyboard. So I did some more digging - actual digging. I dug the down arrow cursor key out and it looked like there was chunk of lint in it. With the key taken apart the machine DID NOT have the issue. I cleaned the key and put it back together and it started scrolling again. I took it apart again and cleaned it better and now I think it works. If it continues to give problems I think I will need to replace the keyboard (top case assembly). Sorry for not recognizing this earlier and thanks for the respones.

 

[TonyAguila]

UPDATE: I tried once more to disconnect the internal keyboard and connecting a USB keyboard and the scrolling issue seemed to go away - and I was able to OPTION-Boot and boot to diagnostic mode with the USB keyboard. So I did some more digging - actual digging. I dug the down arrow cursor key out and it looked like there was chunk of lint in it. With the key taken apart the machine DID NOT have the issue. I cleaned the key and put it back together and it started scrolling again. I took it apart again and cleaned it better and now I think it works. If it continues to give problems I think I will need to replace the keyboard (top case assembly). Sorry for not recognizing this earlier and thanks for the respones.

Resetting PRAM could possibly cure some of the residual issues. To perform this manually…

Reboot into Safe Mode. In Terminal, enter

sudo nvram -c​

and press Enter/return. Enter the Administrator password and press Enter/return. Then enter

sudo shutdown -r now​

and press Enter/return to reboot. Keep in mind that resetting the PRAM will disable TRIM on your SSDs. To turn it back on, enter

sudo trimforce enable​

This will inform you that a reboot is required.