Inspiron

[jasmith00]

Hello, I have a Dell Inspiron 5551 and bios complains that the power adapter cannot be determined. I am using a Dell OEM 45w adapter. How can I fix this? It's throttling my cpu to .5 ghz

I've tried several power adapters, many OEM, and all give this message. This leads me to believe it's not the adapters at fault here.

[ejn63]

First thing to try is a new OEM Dell adapter -- if it's recognized, the original adapter is faulty.  If not, replace the DC jack inside the system.  One of these usually solves the problem.

This model does not charge by USB so that's not an option -- you need an OEM Dell adapter that the system recognizes for the battery to charge and for the system to operate at full power.

[jasmith00]

Hi, thanks, I've definitely got OEM adapters... the one that was original to the laptop, one I just recently purchased, and two that i've borrowed. All are Dell branded adapters made for this model (business shop here so we have several of the same model circulating around).

The system knows the adapter is plugged in, so the jack is probably fine

[jasmith00]

Found that if I disable Intel SpeedStep in bios I get another ghz back at least. Still not full power and the battery won't charge.

[ejn63]

There are two possibilities:

The jack is faulty (about $30 or less), or

The mainboard (charge circuit) is bad (figure at least $150 for a replacement -- possibly more depending on the CPU and whether or not you change it yourself).

You can decide which to replace next before moving onward.