Laptop 3x slower when plugged in; Unrecognized adapter

Will anybody reply or is that too much to expect? Is this a support forum or just a place where Dell owners can freely have monologues about problems they have with Dell products?

Hi mehaga,

Dell has customized the AC adapter according to the system requirements. The unrecognized AC adapter indicates the AC adapter is powering the laptop but may not be charging the battery on the system. Its not recommended to use third party AC adapter as the Voltage and the Amps may differ. It’s unusual that AC adapter could slow down the system but if AC adapter is not able to take the load of the system the system may slow down. Also, using third party adapter could malfunction the system board on the computer.

One more thing. The problem is not that "adapter is not able to take the load of the system", because the system works fine if I unplug the adapter. If it can handle the load on battery alone, why would it not be able to handle the load with an (unrecognized) adapter?

Also, it most definitely slows down, and becomes almost exactly 3x slower - I tested.

Hi, 

Adapter I am using is the Dell adapter I received with my laptop, NOT a third party adapter. 

If the AC adapter isn't recognized, the system will run as if on battery all the time. 

First thing to try:  new Dell adapter.  If that isn't recognized, the problem is with the DC jack or mainboard.  From your description, your mainboard is likely bad, but since it's far more expensive than the adapter, try a new one first.

If the adapter is not detected, the system will run at low speed all the time.  And the adapter carries the system warranty - if the warranty on the system is valid, it is on the adapter as well.  The battery carries a 12-month warranty regardless of the warranty on the system, but the adapter (assuming it's not physically damaged) carries the same warranty as the system.

Sorry, what I meant is:

- If the adapter is not plugged in, it will run exactly the same as when the adapter is plugged in and detected properly recognized as Dell adapter

Thank you for your reply, ejn63.

No, it will not run as if on battery, that is what I hate the most about it. It will run slower than it does on battery. I wish it't a bad motherboard, because the laptop is still under warranty, the adapter is not (only 6 months warranty on it, bought about a year ago).

Did you set up the power management to run that way?  The default is that the system runs slower on battery, but that setting can be overridden at the UEFI level or under Windows.

Is Windows factory installed, or did you do the installation manually?

Hardware:  If the system intermittently doesn't recognize the AC adapter, it's likely a connection problem at the jack (either the adapter plug or the jack itself).

Software:  it's impossible to say whether you've properly installed the power management drivers.  I'd check with the ubuntu community on that one. 

Thank you for your help, ejn63.

It came with Ubuntu factory installed, not Windows, but I installed a different version of Ubuntu manually. I think it uses legacy BIOS, not UEFI.