Laptop won't turn on...

[Sin(x)=0.933...]

Hey there.

I'm troubleshooting a laptop and I'm getting no boot, black screen, but the power LED lights up. When I unplug the battery I can get into the windows recovery options page and I can attempt to click on "continue to windows," but the problem is as it tries to load up windows it turns off (of course when this is happening it's plugged into the wall). I'm thinking the battery is faulty here... but I just want to make sure. The thing is, there are plenty of people online saying that a laptop should still turn on regardless of whether the batter is connected or not, but that's not what I'm experiencing. Laptop info: latitude 7490.

Thank you very much!

[Wohaaa]

26 minutes ago, Sin(x)=0.933... said:

The thing is, there are plenty of people online saying that a laptop should still turn on regardless of whether the batter is connected or not, but that's not what I'm experiencing.

it should, definitely should, if you open the laptop and unplug the cable that attaches the battery to the motherboard and plug the charger in then it's supposed to turn on. Heck that's exactly what happened with my sister's laptop. The battery is still in the enclosure but disconnected, so effectively not there, and the laptop runs off the wall entirely. The only reason this wouldn't work would be if the laptop used a design such that the battery acted as the middleman between the wall and the computer, and in that case, unplugging the battery would make the computer never turn on, even when plugged in, which isn't the case.

 

I don't think the battery's the thing at fault here if it's completely disconnected from the internal motherboard and running off the wall. If it's immediately giving Windows recovery options, I'd reckon it's faulty storage instead.

[RollyShed]

2 hours ago, Sin(x)=0.933... said:

I'm troubleshooting a laptop and I'm getting no boot, black screen, but the power LED lights up. When I unplug the battery I can get into the windows recovery options page

It sounds as if the battery has a short so even with the power supply producing power, it isn't able to give enough voltage.

Have you tried measuring the battery voltage with the battery removed?

It should be near 12 volts or 7.6 volt depending on the number of cells in your version.

Do you have a DVM?

[Sin(x)=0.933...]

19 hours ago, RollyShed said:

It sounds as if the battery has a short so even with the power supply producing power, it isn't able to give enough voltage.

Have you tried measuring the battery voltage with the battery removed?

It should be near 12 volts or 7.6 volt depending on the number of cells in your version.

Do you have a DVM?

Nope, I haven't... and I don't have a DVM; although I should probably get one, thanks!

[Sin(x)=0.933...]

20 hours ago, Wohaaa said:

I don't think the battery's the thing at fault here if it's completely disconnected from the internal motherboard and running off the wall. If it's immediately giving Windows recovery options, I'd reckon it's faulty storage instead.

I understand where you are coming from, but the problem is why wouldn't it turn on at all when the battery is plugged in? Thanks!

[RollyShed]

4 minutes ago, Sin(x)=0.933... said:

I understand where you are coming from, but the problem is why wouldn't it turn on at all when the battery is plugged in? Thanks!

I don't understand what is being said either. It doesn't make sense. If the battery is shorting things, it won't go.

 

As for having a DVM, how do you live in the modern technical world without one? Do you ever check batteries for anything? It isn't going, is the wire broken, are the batteries flat, is the bulb (filament) broken?

 

Personally I've been using one throughout today, a couple of jobs this morning on faulty laptop power supplies another one this afternoon.

Why is the guitar tuner not working, is it the battery... so it goes on.

[Wohaaa]

On 7/23/2022 at 9:25 AM, Sin(x)=0.933... said:

I understand where you are coming from, but the problem is why wouldn't it turn on at all when the battery is plugged in? Thanks!

Well there could be more than one problem then.

One thing at a time, my sister's laptop also had the same thing where it wouldn't turn on if the battery was plugged in.

So immediately bypassing that and plugging it into the wall you run into another issue where it turns off as it loads into windows, hence why I theorised a faulty install.

 

It's uncommon but depending on the age of the laptop it could definitely be more than one issue, especially if the battery being faulty caused something else to go wrong. The only way to know would be fair testing. If I were you I'd try another boot drive with the battery unplugged and the laptop running off the wall to see if I can log into windows. If so then I'd try again with the original drive, if that one fails it means there's a drive issue. Then I'd try that new drive with the battery plugged in (but do be careful as, if the battery is faulty it could affect this new drive as well).

 

It's all about fair testing and narrowing down the problem using fair tests