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Battery not charging: is it DC power jack or motherboard fault?

  • Battery
  • Power
Last response: in Laptop Tech Support
May 12, 2016 6:03:42 AM

When I boot my Inspiron 15R-5537, I get this message:

"The AC adapter wattage and type cannot be determined. The battery may not charge. The system will adjust the performance to match the power available. Please connect a Dell 65W AC adapter or greater for the best system performance."

The AC adapter (it is a 90-watt AC adapter) does not charge the battery and the laptop keeps in low-power mode, it is, the CPU clock gets stuck at 780 MHz, while it can go up to 2,3 GHz in full power mode. When I say it doesn't charge the battery, I mean it starts charging for a while, and then the power LED turns off and the battery icon says it's connected, but not charging. I've already bought a new 90-watt charger directly from Dell and it didn't fix the issue. When I use the battery alone, the CPU can get to 2,3 GHz just fine, meaning it isn't the battery either.

So I'm left with two options: it's either the DC jack, or the motherboard. From what I've read, this DC jack has a hole in the centre which receives the pin in the AC adapter connector, and this pin tells the laptop which is the wattage the power adapter can supply, which is 90 W for this laptop model.

Do you think replacing this jack can solve this issue, or is most likely a hardware issue with the motherboard?

This is what I'm talking about:

More about : battery charging power jack motherboard fault

May 12, 2016 6:13:40 AM

Some adapters are 'smart' adapters and while they might provide power, they have specialized wiring to determine if it's a correct charger. Naturally this becomes problematic if you get a generic aftermarket adapter as the laptop becomes confused.

Considering that you spec that the adapter is a 90w adapter and the laptop is telling you to put in a Dell 65w - I'm thinking you replaced yours with the aforementioned aftermarket adapter? You might need to bite the bullet and find the original Dell part.
May 12, 2016 7:05:06 AM

It's an original brand new AC adapter from Dell, bought from their online shop. Dell has a list of compatible accessories for each laptop or desktop model, and this AC adapter was listed there, that's how I bought it. The original AC adapter also provided 90 W, which is obviously much greater than the minimum 65 W required, according to the warning. Thanks for the reply, I appreciate your help.

I disassembled my laptop and removed this cable from the motherboard. I inspected the power connector on the motherboard and it's perfect, like new. No oxidation, no damaged tracks on the PCB, and the battery pins also are brand new. I believe this cable has a faulty pin (even though it looks in perfect condition), which is responsible for identifying how much power the AC adapter can supply.
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May 12, 2016 8:41:20 AM

If it's a new OEM Dell piece, then I would return it as something is definitely wrong then...

Best solution

May 23, 2016 11:41:02 AM

Guys, great news!. I replaced this cable and it worked!:)  I accessed the BIOS menu and AC Adapter Type was reported as "90W" like it should. The AC adapter is able to charge the battery again, and the CPU can now reach max Turbo Boost clock (2,3 GHz) with only the AC adapter plugged. I returned the AC adapter to Dell as the original is working fine.

I'm so happy that it worked, I was smart enough to think about replacing this cheap cable first instead of the motherboard, which wouldn't be viable. It was risky but it was well worth it in the end. I'd like to say thank you guys for all your support. I hope this solution can help other owners of Dell laptops as well :D 
May 24, 2016 9:31:17 AM

So - just to be clear for other Dell owners, you replaced the power jack/cable assembly which the charger plugs into and which connects to the motherboard?
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