"Plugged in, not charging"

I have and have had the same problem.  It is your motherboard.  I just talked to the service dept. we took it to and they said they cannot even find a replacement.  I had it replaced once under warranty after less than a year, and now a second time a year later.  He said I should contact Dell and ask them to replace it, but I cannot find a place to contact that won't charge you.

I replaced the battery in my Inspiron 1526 yesterday because it would not charge (for months so I figured it was sufficiently dead).  With the new battery installed, I still get the "Plugged in, not charging" message on the battery meter.  The battery meter decreases when I don't use the adapter and stops decreasing when I use the adapter.  It seems that the battery is simply not charging. I've updated and re-loaded drivers and the message persists.  It seems that there must be a problem with the charging circuit.  Anyone had similar issues?

Have you checked the option "Disable battery charging"?

It's under Battery life tab of Dell battery meter

When you click on the battery icon in the power meter, does laptop battery data look ok?

If there's no info communication with the battery is not working

if it looks like bogus info, try the other battery and compare info

First thing, i'd check the DC jack and the jack plug (bent center pin).

If that looks ok, go into BIOS setup and check if the AC adapter is listed by it's capacity. (like 90 Watt or similar)

If it's not listed, battery is not charged - most likely cause is an id chip problem inside the adapter, assuming DC jack and plug are ok.

I have the same problem and foolishly bought a new battery. Maybe it is the motherboard but it seems odd that you can diagnose that from a distance and that some people have this problem so soon after they buy the computer.  I have no other symptoms of a motherboard problem either.  A quick google shows this to be a rampant problem: e.g,   http://www.howtomendit.com/answers.php?id=141277 or this one which suggests we all ought to stay away from Dell: http://www.howtomendit.com/answers.php?id=141277

My own experience with Dell is that it is very difficult to get a knowledgable person on the phone.

My Blue Inspiron 1526 had the same problem.  I bought a new battery to no avail.  I tried three different Dell branded AC adapters to no avail.  Scoured the net and found one cause that made sense - a bad power board.  Bought a new power board off eBay for under $6 shipped (p/n 48.4W006.021).  Took apart the laptop (not easy or intuitive btw - attempt at your own risk, although there's some videos and other documentation on the net that helps), replaced the power board, and Viola!  Now I can charge both the new and old battery using any of the three AC adapters.  I'd only suggest this fix to mechanically-inclined types.  If you're still under warranty (unlikely?), I'd guess that this voids your warranty too. Good luck!