Chromebook 11-v025wm black screen issue

[MClark30]

**Preface** Been building and repairing PC's for nearly 20 years...

Got a Chromebook 11-v025wm I'm working on. Customer said it won't turn on.  I can see it's charging/charged and Power LED works, but the screen stays black. Acts like it is stuck in a sleep state. Here's the things I've tried/recorded about the laptop:

1. Plugged AC adapter in and LED light was amber color
2. Power LED is white, stays on for 15 seconds, goes off for 5 seconds, and back on for 15 seconds repeatedly. Like a sleep mode indication
3. Let the laptop charge over night for about 10 hours. Charging LED light is now solid white, no longer amber.
4. Power LED still doing 15 on/5 off
5. Held power button on keyboard for 20 seconds and the Power LED stays off. Pressing the Power Button causes the Power LED to come on and do the 15 on/5 off cycle as before
6. Opened the laptop up and disconnected the battery for 30 minutes. Plugged back into the board and same result of Power LED 15 on/5 off
7. Checked all cables and re-seated with battery disconnected. Re-connected battery, nothing changed
8. With laptop fully shut off, tested the Hall Sensor by putting a magnet near it and removing it. This caused the Power LED to turn on and then do the 15 on/5 off light cycle. Unsure if this is normal, but I would assume only the power button could turn the device on, not the Hall Sensor...

I have not tried any USB restore or anything like that. I also tried the trick of disconnecting battery, plug in ac adapter and then plug in battery. It did nothing.

Any ideas would be greatly appreciated.

Edit 1: Disconnected the Hall Sensor from the board and still no difference. A new thing I found was if I disconnect/reconnect the battery, then connect the keyboard and press the Power Button, it won't turn on. It will only turn on once I connect the ac adapter. After that, I can remove the ac adapter and use the Power Button to turn off by holding it for 20 seconds and then back on after pressing it...

[sandytechy20]

@MClark30

Thanks for posting. It is a terrific place to find answers and tips! 

I understand that Chromebook is not turning on and also see that you have done multiple troubleshooting steps to fix it, I will be delighted to assist you here.

Try doing a power wash on Chromebook.

Here the Youtube video which you can refer to do that:-  https://www.youtube.com/watch?v=XTNU_Gqw394

If it does not work, I am sending you a private message. Please check the mailbox icon at the top-right corner of this screen.

Please check your Private message icon on the upper right corner of your HP Forums profile,

Next, to your profile Name, you should see a little blue envelope, please click on it.

Please reply back on the public post as this Private message box is not monitored.

I hope this helps resolve this issue completely,

To thank me for my efforts to help you, please mark my post as an accepted solution so that it benefits several others and please give the same post a Kudos.

Cheers.

[MClark30]

Thanks, Sandy. I actually cannot do a power wash because there is nothing on the screen. At this point, either the screen or motherboard has gone bad. I know at least it's getting power as the power LED light comes on when opening the lid or pressing the power button, but I don't get any backlight or nothing from the screen. I have no way of testing another screen on it to see if I am actually getting something from the OS. I can't even boot to a USB for recovery of the OS because nothing shows on the screen.

I think the customer doesn't want to put any money into it, so I'll just leave it as is. Thanks for your help!

[sandytechy20]

@MClark30

Thanks for the reply.

I appreciate your time and effort.

I am sending you a private message. Please check the mailbox icon at the top-right corner of this screen.

Please check your Private message icon on the upper right corner of your HP Forums profile,

Next, to your profile Name, you should see a little blue envelope, please click on it.

Please reply back on the public post as this Private message box is not monitored.

I hope this helps resolve this issue completely,

If this helps, please mark my post as an accepted solution so that it benefits several others and please give the same post a Kudos for my efforts to help.
Take care and have a blessed week ahead.

Cheers.

[mcsvt]

I have been looking for a solution to this issue for 2 years and we have hundreds of HP Chromebooks with this being the most common problem. I can see from this forum that there are hundreds of people with the same problem looking for answers. There never seems to be a solution posted and I know it is a hardware defect that happens to the screen. It seems it happens about a year out so just past warranty so the calling in is no good. The private message doesn't offer solutions so is this something we just have to accept and buy new chromebooks? HP must know there is a problem and could post a real solution.