Acer Spin CP713-2W-5874 Screen, Keyboard, and trackpad issues

speleo55

Model: CP713-2W-5874

The display, keyboard, and trackpad are all not functioning on my Chromebook. I can connect an external (USB C) display, wired keyboard (USB), and Bluetooth mouse, and those all work. I've powerwashed, reinstalled ChromeOS from USB, and upgraded to the latest firmware (108.5359.75) with no luck. I've also opened the back, disconnected/reconnected the battery and the ribbon cable for the display.

Where this gets interesting is that while generally none of these components work, they do briefly when it boots up. If I press Refresh+Power, I see the Chrome logo, then a quick flash of the login screen before it disappears - albeit very dim, as if the backlight isn't on. If I go through the process to powerwash my Chromebook, it says it requires a reboot first. When I do that, I get the Chrome logo, and a brief flash of the login screen before it disappears, with full brightness. If I use the trackpad in that brief moment, the cursor moves as well. Once the screen goes off, the trackpad stops working. With an external monitor connected, the display will shift over there. Without the monitor, it just turns off. Here's a video of its behavior: https://youtu.be/KciCsKT7p-U

Any thoughts? I thought it might have been software related since it works briefly, but since the recovering via USB didn't fix it, I'm not sure anymore. This first started awhile back, I used my Chromebook as normal one day, set it down, picked it up a few days later, and it was doing this.

 [Edited the thread to add model name to the title]

JackE

>>>display, keyboard, and trackpad are all not functioning on my Chromebook>>>

Unusual that all would be affected as each has its own plugin to different i/o sections of the mainboard. Did the machine sit unused in humid conditions for long periods?

speleo55

No, it rarely made it out of my apartment, and never sat anywhere else for an extended period of time.

JackE

Is it still under warranty?

speleo55

Unfortunately not. The issue started shortly after the warranty expired.

JackE

>>>Where this gets interesting is that while generally none of these components work, they do briefly when it boots up.>>>

>>>The issue started shortly after the warranty expired.>>>

Did all three start behaving like this suddenly --- at the same time --- for no apparent reason?

speleo55

To my knowledge, yes. I used the laptop one day, set it on the coffee table, picked it up a few days later, and it wasn't working. Nothing odd happened in that time period that would have led to this. As for everything happening at once - to be fair, I didn't connect external peripherals immediately. There may be a chance that only the display stopped working first, and then everything else stopped working later, but my working assumption is that they all stopped working at the same time. While it doesn't respond to any input from the keyboard while using the computer, it does respond to a hard reset or entering recovery mode when pressing ESC and/or Refresh with the power button. Which also leads me to believe it's not a hardware issue - ie pressing the refresh button when using an external monitor does nothing, but if I press that and the power button it immediately does a hard reset.

Another thing I've found while testing, is that HDMI doesn't appear to work for an external display. USB C works but HDMI doesn't.

speleo55

Another thing worth noting, when I press ESC + Refresh + Power, I don't see the 'Chrome OS is missing or damaged' screen. The screen is blank and the external monitor does not work. Inserting an SD card with the recovery media appears to work though, as I can go through the steps to re-install ChromeOS and once that's completed, when I power it back on, it comes up as a new install of ChromeOS and needs to be setup.

Commodore_1995#

Are there any battery symbols in any of these locations?

speleo55

No battery symbols, only MicroSD and USB as shown in your picture.

speleo55

Not sure if this is helpful or not, but another symptom I found is that if you click the clock in the bottom right to pull up quick settings, the screen brightness is at zero. If you raise it, then click out and back into quick settings, it resets itself to zero. That may just be the case if it doesn't detect the screen though. Not sure if it's actually any help in troubleshooting or not.

JackE

>>>While it doesn't respond to any input from the keyboard while using the computer, it does respond to a hard reset or entering recovery mode when pressing ESC and/or Refresh with the power button.>>>

>>>my working assumption is that they all stopped working at the same time>>>

It's acting as if the BIOS is initializing all the i/o hardware OK. But they're not all being picked up by ChromeOS for some reason.

So since there seem to be no convenient battery disconnect pinholes that @egydiocoelho was looking for, you probably should disconnect the charger, remove 9 screws on the bottom cover, pry the cover off starting from the side opposite the lid hinges, and pull the battery connector off the mainboard. Then press and hold the power button for a few minutes to try to drain all residual changes.

Then button it all back up to see what happens.

speleo55

No luck with that. It was perhaps a little excessive, but I held the power button for 5 minutes with the battery disconnected and there's no change. My understanding is there's no CMOS battery with this model, otherwise I'd disconnect that as well.

JackE

>>>My understanding is there's no CMOS battery with this model, otherwise I'd disconnect that as well.>>>

Yes. In theory, the chip doesn't need to be battery maintained and can't be easily changed after it's been programmed. So it's probably more secure and cheaper than electronically re-programmable chips. But it practice, it can still lose its mind by over-heating, mechanical shock, voltage spikes, high energy radiation, etc that can irreversibly disable it Then the only remedy is a new mainboard.

However, your description still sounds like a problem the comes after the BIOS has done its job of initializing all the i/o components. While you were in there disconnecting the battery pack, did you also try to re-seat all the accessible ribbon cable connectors to the keyboard, touchpad and screen?