Dell laptop power supply question

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I have a Dell Inspiron 9100 laptop that has worked happily for about
two years. When I boot the system, I recently started receiving a
fairly common message to the effect of

"The system cannot determine the AC adapter type. This will prevent
optimum system performance." When this happens, the adapter will not
simultaneously charge the battery while the system is running.

My own research into this problem indicates that this can mean that A)
a third-party power source is attached (not the case), B ) the laptop
power connector is failing, or C) the power supply is not providing the
minimum 150W to allow it to charge the battery. I understand that the
power connection jack is the most likely cause; however....

Is there something that could cause a power adapter to fail in such a
way that its power output would *drop* as it warms up? When the supply
is stone cold, it works normally. Even if warm, sometimes unplugging it
from the wall and replugging it (allowing it to discharge) will allow
it to function correctly when I restart the laptop.

I took the supply to a local shop for testing, and when they plugged it
into a laptop there, it worked, showing 150W, but I also realized the
supply had been detached from AC power for several hours. And when I
got back home that afternoon - several hours later - it worked. But,
this afternoon, after being plugged in all day, the messages returned
on boot up - but after moving the supply to a different outlet, it
worked -- as if something internally "reset" once power was removed.

It finally occurred to me that the supply is still producing power,
but, over time, not enough to do the "whole" job. A voltmeter tells me
its putting out 18.5 V when the specs say it should be producing
19.5V...bottom line, I'm hoping the power supply is the problem, not
the laptop power jack..


Many thanks in advance,

Re: Dell laptop power supply question

On 17 May 2006 17:36:40 -0700, wrote:

(snip problem description)
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Dunno, but if you check the Dell site there have been recalls for certain laptop
PSU's.  Yours just might be from one of the recalled batches.  Worth a look.

Re: Dell laptop power supply question

Well, my PSU wasn't among the recalls, but I did find a new replacement
power supply for the system at for $62, and that has
completely solved the problem.

In a word, YAY!!!!!

I was optimistic the moment I plugged it in, because the little green
power light was 10x brighter (okay, maybe that's an exaggeration) on
the new one compared to its predecessor.

Laptop (and its owner) are now all happy.


budgie wrote:
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