very strange laptop issue... power button does nothing

[UltraMega]

So a customer brough me a dell laptop that he bought used. It works but the power button doesn't do anything. 

 

When opening the lid, the laptop turns on every time almost like opening the lid works as a power button. At no time does the power button do anything, holding it down does not force the laptop to turn off. I was thinking the power button itself was the issue and I was going to replace it but after running some tests I determined that the power button will turn off the laptop after I unplug the battery and reset the bios, but once it boots up fully the power button goes back to doing nothing. 

 

I read there are some laptops with a feature for turning them on when the lid is opened but I don't see any settings for that in the bios, and if that were the case I figure the power button would still work. I'm kinda at a loss here. My best guess is the motherboard has some kind of unique issue. Any thoughts?  

Edited November 3, 2021 by UltraMega

[UltraMega]

Some more thoughts after reading more about this...

 

Newer dell laptops have a "lid power on" option and there should be an option to enable/disable it in the bios. This laptop is basically acting as if this feature is on but the option to disable it is missing. 

 

There was an update for the bios from this year (laptop has an intel 7th gen CPU) and I did the update, still no option to disable lid power on. 

Edited November 3, 2021 by UltraMega

[pio]

I know it sounds absolutely silly asking this on a tech forum......BUUTTT.....

 

Have you checked Windows power settings?  What about any drivers that might control power?  I think I've seen some options in CCC regarding power on my Ryzen APU laptop.  Since the button seems to work sometimes and not others, and it works after a CMOS reset but stops working, its sounding to me like a driver or software "bug" that's getting turned back on once it boots.

And sometimes, the simplest answers can be overlooked.

[schuck6566]

Battery/Power Supply issues? Sometimes not enough battery level will stop the power button from turning on mine.Found out when using aftermarket brick.Would power up on it's own with lid open after sitting plugged in for hours, but not with the power button unless I left the lid closed for a couple days then tried the button.Different brick straightened that out.

[UltraMega]

2 hours ago, pioneerisloud said:

I know it sounds absolutely silly asking this on a tech forum......BUUTTT.....

 

Have you checked Windows power settings?  What about any drivers that might control power?  I think I've seen some options in CCC regarding power on my Ryzen APU laptop.  Since the button seems to work sometimes and not others, and it works after a CMOS reset but stops working, its sounding to me like a driver or software "bug" that's getting turned back on once it boots.

And sometimes, the simplest answers can be overlooked.

Yea I checked that. I was also wondering if it could be some weird driver thing but reformatting didn't help. 

 

1 hour ago, schuck6566 said:

Battery/Power Supply issues? Sometimes not enough battery level will stop the power button from turning on mine.Found out when using aftermarket brick.Would power up on it's own with lid open after sitting plugged in for hours, but not with the power button unless I left the lid closed for a couple days then tried the button.Different brick straightened that out.

The bios has a battery health check and it says the battery is in excellent health. 

 

I also ran the Dell hardware diagnostic tool from the bios and it found no issues. 

[ENTERPRISE]

I have had issues similar to this with a faulty charge circuit. I removed the battery altogether and only had the mains power in. Button would work normally for turning the laptop on and off. 

 

However upon re-introducing the battery, the problem would come back. I never finished fixing the laptop as customer found it silly to fix but my best guess was either a bad battery (Irrespective of what health check may say), or a faulty charge circuit creating a short of sorts.

[UltraMega]

34 minutes ago, ENTERPRISE said:

I have had issues similar to this with a faulty charge circuit. I removed the battery altogether and only had the mains power in. Button would work normally for turning the laptop on and off. 

 

However upon re-introducing the battery, the problem would come back. I never finished fixing the laptop as customer found it silly to fix but my best guess was either a bad battery (Irrespective of what health check may say), or a faulty charge circuit creating a short of sorts.

I removed the battery and tried to turn it on with the charger plugged in and it didn't boot up windows, no video output. It turned on, but didn't boot and this was the only time the power button did actually turn it off when I held it down. After that it took a while before it would boot to windows again. 

 

Perhaps if I had persisted more before I reconnected the battery it would have eventually booted again and I could test that but this isn't the kind of battery that is supposed to be disconnected at will, it's under the bottom panel and connected with a cable directly to the mobo, and screwed in. 

 

I may try again though just out of curiosity... It's an interesting suggestion. 

[UltraMega]

15 hours ago, schuck6566 said:

Battery/Power Supply issues? Sometimes not enough battery level will stop the power button from turning on mine.Found out when using aftermarket brick.Would power up on it's own with lid open after sitting plugged in for hours, but not with the power button unless I left the lid closed for a couple days then tried the button.Different brick straightened that out.

It doesn't stop it from turning on, it turns on reliably but only from moving the lid and not from the power button at all. 

 

 

The customer only bought this laptop because the case on his other laptop is falling apart and I guess he thought that would be harder to fix but after talking to him about it he decided to order the parts for that laptop himself and he's dropping it off later for me to do the repair. Apparently, he moved here (CA) from Texas temporarily to do something related to rebuilding homes that burned down due to the recent fires so he is working like 24/7 since I assume he feels his work is very important. He probably thought the repair for his main laptop would take a lot longer, and normally I wouldn't order parts before having the laptop in hand just to avoid any mis match issues but since his work is demanding I walked him through finding the part himself so he can drop the laptop off with the part and the repair can get done quickly. 

Edited November 4, 2021 by UltraMega