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Dell Latitude D600 - AC Not Charging Battery


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Dell Latitude D600 - AC Not Charging Battery

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Since I've now recently been ensnared in this problem of Dell computers which suddenly and inexplicably no longer seem to be capable of charging the laptop battery - although the AC adaptor still appears to be fully functional in terms of powering the laptop, I thought I would attempt to post the definitive thread on this issue, in an attempt to identify a solution.

I have a probably 5+ year old Dell Latitude D600 laptop, purchased used, and running Windows XP Professional without any problems for the past 3-4 years. As an electronics engineer, I have no problem in diagnosing and repairing minor eletrical problems, to include laptop computers.

About 3 days ago during a reboot, I got the message saying that "Warning: An unknown AC power adapter has been detected, > preventing optimal system performance. Strike the F3 key (before the F1> or F2 key) if you do not want to see power warning messages again.".  Not knowing what to make of that in terms of the implications, I hit F3. Only a day or so later, I noticed that one of my two laptop batteries had drained to zero and appeared to not be charging correctly. I checked my two laptop batteries using the built-in test button, and both showed OK, although one was nearly fully discharged. So, we know the batteries are OK.

In checking the AC adaptor using a voltmeter, I checked the output, and the output was right up to spec with the output right at 19.5V. I examined the laptop AC connector port and it appeared to be both solidly soldered to the motherboard with the connections all clean. Since I know that the AC adaptor has very few moving parts (few = none), and since one of the batteries I have is relatively new, I'm pretty sure the batteries and laptop are not the problem. So, the battery and the AC adaptor upstream all the way to the laptop all appears solid.

I'm somewhat hazy on the internal mechanism in the laptop that detects a battery level discharge and routes power to the battery for charging, while the laptop is in a powered-on or powered-off status - although I will assume it functions somewhat similar to the alternator in a car, and how a car battery is charged. So, something (physical or software) has happened that has thwarted the charging mechanism or sensor. My guess is something physical, since during the time of my problem, no software changes come to mind. That suggests a physical problem. I've read some threads suggestions problems with the motherboard, but I speculate that those are mostly nonsense - since no other problems associated with the motherboard have emerged. My best guess is that there's some problem with the Power Circuit Board, although I can't discount some other sensor failure problem that has caused the battery charging to fail.

This represents the extent of my best sense of the problem. I won't discount all end-users problems that may possibly originate at the battery or AC adaptor level, but I have definitively eliminated those issues as problems on my end (so in proposing answers, don't offer up either of those - or the "motherboard" issue as solutions either). Any other possible suggestions on the way to a possible solution and if this has been as large a problem as what I've read - any input from Dell on a solution? I'll happily accept the fact that nothing lasts forever without breaking, so I'm not sure why I've seen nothing very compelling on this subject from Dell - since there are no shortage of spare parts out on the market and I'm happy to effect my own repair, but I need to know which component has failed so that I can replace it (since I'm simply not going to engage in a "random" repair strategy).

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  • I'm about to give up on my D600 Latitude, which is a shame as I've bought DVD Drive, hard disk, battery and 2 power adapters to make it useable. The adapter isn't charging the battery anymore and the D600 refuses to work on AC-only. Since getting this genuine DELL PA-10 about 6 weeks ago the charging behaviour has got steadily worse. Initially you had to jiggle the jack plug a bit and hope the charging light would appear.

    Now however it has given up the ghost completely.

    Many thanks for all the info in this thread - it certainly has changed my mind about Dell's cynical unreliability across a large number of their laptops.

    Time to cut my losses - at least I can re-use the disk drive, shame I can't get any more use out of the DVD-drive.

  • Although it's been a while since I've revisited this posting, I thought it was relevant to make a return visit, since I may be in possession of some new information, that may be of help to folks. 

    Way upstream, I noted that I had purchased a used base unit for my D600 from eBay, back last January.  Unfortunately, after swapping out all the components (hard drive, screen, Wi-Fi, CD-DVD Drive, keyboard, battery), the laptop fired up just fine, but I still received the A/C Adapter Not Recognized message, and the battery would not charge.  Just this week, the replacement base unit apparently gave up the ghost (the A/C adaptor light would go off when plugged into the laptop), and the laptop would no longer power-up.  Luckily, I purchased an extended warranty through Square Trade Warranties, which they readily honored - although not with a repair, but with a complete refund of the original eBay purchase price (nice!). 

    With no way to access my hard drive data, I dug out my old D600 base unit (from under the couch), and re-installed all the components and fired up the unit (which powered right up).  I guess the onboard power supply had failed since last January, because I got the Set-Up message to re-set the date/time - which I did.  After the unit re-booted to the Desktop, it was only then that I noticed that the battery charging light was Green and a quick check showed that the battery was being charged.  In no time, I had both laptop batteries fully charged (confirmed by the onboard test button).  The laptop will also "shift" to battery power, just like it should when the A/C adaptor is unplugged. 

    So, what do I make of this change of events?  Since I'm still using the same A/C adapter, the same two laptop batteries, and now the same base unit that previously would not charge the batteries, I'm wondering whether this problem actually resides somewhere with the onboard battery charging algorithm that resides hard-coded somewhere on the motherboard.  I'm speculating that the loss of all power to motherboard (and the restoration yesterday), somehow allowed the prior "fault" to reset itself, and reallow the standard battery charging to work properly.  I've speculated about trying to induce the original fault again, but for a variety of practical reasons I'm disinclined to try to recreate my original problem all over again.  I guess I'll offer this solution up to others who might want to try this.  I think that to try this, you would need to disconnect all power sources, pull the battery pack and remove the onboard backup lithium battery pack (which is hiding behind the little door along the edge of the cavity which houses the laptop battery pack.  I'd love to believe that this is a (or the) solution to this problem, but I just don't know.  I'm certain that it was the complete loss of the power to the base unit (versus being under the living room couch for 10 months) that had something to do with the restored charging capability.  If this works for people, I'd love to get some feedback (and $5 from each person payable to my PayPal account -- just kidding . . . ).  Good luck.

  • i have two d600's with three batteries and both a p-10 and p-12 adaptors. Everything works fine on the older machine but when used on the newer machine the led on both adaptors will not stay lit when plugged in. Did this happen on yours?  The newer machine runs fine on battery power but will not recharge from either adaptor.  I'm wondering if I should try a complete power down like you suggested to see if this will work. It seems to me that you are correct in assuming that this is a software glitch on Dells part after the battery "bomb" scare and not a hardware

  • Yes, LED indicator light on the A/C adapter(s) (I have a P-10 and P-12 also) would "go out" whenever the adapters were plugged into the other laptop base unit. I'm not sure what was causing that "fault".  I would at least take a look at the connections on your Wi-Fi transmitter card (underside, small panel on side in the middle), but nothing I did seemed to solve the LED light problem - as this was a brand new issue for me. 

    On the other part about trying to "power-down" (fully power down) the whole unit, I would certainly give that a try.  Literally, the only thing you have to lose are your date/time settings, which can be restored lickety-split.

  • Vulcanized Rubber was discovered by accident.  The solution to the "will run the computer, but will not charge the battery" dilemma seems to have been cracked by the motherboard under the ole' couch routine!  I removed the little hidden battery plug for about a half hour, restarted the computer, and for the first time ever got the "power cord not recognized" message, pressed to get into the setup, restored the time/date, continued, and EUREKA, it has now charged the battery successfully!

    You, sir, receive my vote for the Smarter-Than-Dell Award!


    Thank You, Thank You, Thank You!

  • Well, this sort of independent feedback is pretty gratifying.  It's nice of you to report that you were able to "replicate" the earlier experiment, and obtain the same results.  Now if we could just solve that thing about the "cold fusion" puzzle.  Maybe the cold fusion experiement just needs to be conducted under my living room couch?  Maybe not.

    I'll admit that now I'm sorry that I didn't get serious about the $5 contribution to my PayPal account . . . but I guess that wouldn't have been right.  Thanks!

  • A dead cold restart didn't seem to work for me with my D610. However, I bought an EXTERNAL charger from mambate on eBay, and it has solved my problem. I already have two batteries, and I can be charging one externally while I run on the other. Not quite as simple as an internal charger, but adequate.

    NB: Dell would probably frown on this solution, as in, this voids warranties. The battery doesn't seem to mind, as far as I can tell. The charger heats up, but the batteries remain cool.

  • If it helps anyone else, I can vouch for this working on my D610 too. My battery refused to charge and the BIOS would not recognise that any external power supply was connected. I tried other batteries and AC adapters that were known to be working to no avail. Although the PC would operate (albeit without charging the battery) on AC power with a battery installed, it would switch off if I removed the battery which is not normally the case.

    Before reading this thread I had assumed that I either had a broken DC jack socket or at least had a dry solder joint on the notorious 'third pin' on the mortherboard. I was about to get my soldering iron out and get my hands dirty. Fortunately this thread saved me the hassle. I just took the CMOS battery out for half an hour then replaced, reset the time in the BIOS and away I went.

    The previous occasion before I noticed the problem I had used the PC in a docking station with a 90W power supply so was wondering if this confused it somehow.

    Anyhow, thanks for your perseverence CGD!!!!

  • Hi All,

    I have to admit that I haven't had a chance to read to whole post. But same problem Latitude D820. Changed batteries, changed chargers, still same problem. Finally found post and tried the >

    switch on without adaptor

    when windows screen comes up, plug in adaptor

    It worked!!

    Now I've just got to find out if I have to do that each time I want to charge the battery.

    Cheers all,

    great help.


  • I replied once before but DELL felt my reply was abusive.  Dell has a chip in the AC adapter which talks to a chip in the laptop to confirm that you are using a genuine dell AC adapter.  If the laptop chip does not detect a dell AC adapter it disallows charging of the battery and the bios slows down the CPU (mine went from 1600mhz to 600 mhz).  I have a few DELL batteries (you always assume it is a bad battery) and DELL AC adapters (the next thing you feel must be bad).  The only thing left is a bad chip in the laptop and Dell's solution is to buy a new motherboard.  Customers would have a better clue if they knew about this.  Go into the bios, go to the page with the batteries on it and look at the top where it says "unknown adapter" and you'll know this is your problem.  Then don't bother buying batteries.  I no longer have anyone nearby to test their adapter to see if mine is bad.  I have 2 working ones and both bad?  A third simply had its light go out - guess it got tired of life.

    This is an issue because, as a couple of customers have discovered, the wiring is very weak, it tends to shred and separate.  The signal is in the pin in the middle of the plug.  So, if all the people who have come up with the voodoo of swinging the adapter over their heads in a cemetery at midnight, etc. were to check the bios, they would likely find that it says "unknown adapter" when they had problems and that kicking the adapter around caused it to make the connection again and the bios would say that it is a dell adapter and things would work.  Also, both chips are prone to being blown out - maybe due to the weak wiring situation.  I assume several people are wondering why their windows machine is so sluggish lately unaware that Dell has purposely slowed down the CPU -- because it thinks it is not using a genuine DELL adapter.  Again, if people knew about this Dell practice, they would check there before wasting hours chasing down their problems or $$ buying batteries, etc.  Since I use both DELL adapters and both are "unknown", I'm afraid that my fix will have to be a new motherboard.  However, at the absurd cost of these (they always are), my answer will be a non-Dell laptop, probably used so that 1) I know of problems with the machine which others have seen; 2) usually a great cost savings and 3) usually, any one is pretty darned powerful these days to do real work (instead of CPU hungry games, etc.) and would be just fine.

    I agree with a previous post: a recall should be forced.  I've been trying to find a modified bios to fix these problems.  I'm very sure that the CPU speed is a bios "feature" of Dell's because has software to override the slowdown.  I'm not so sure about the charging thing because I've found nothing to fix that.

    You can find at least 1 writeup from a guy who ripped apart the adapter to chase down the problem.  One thing he did, and is not easy to do, is to pull the chip from a known undamaged Dell AC adapter and put it into the laptop.  This makes the laptop always happy regardless of the AC adapter manufacturer and gets around the problem of flaky Dell wiring of this crucial circuit.

    So, if you have the "unknown adapter", try wiggling the wire and plug around - but I'd suggest to be careful so that you don't change an intermittent wiring problem into a permanent bad one.  You'll have to look up how to test - probably have to power down, reboot, check bios, wiggle wire, repeat until you get it working then do everything possible to keep the wire in that state.  Of course, I am way beyond unhappy about this tactic of DELL - especially since I have been using genuine dell equipment and parts and still am penalized (via an unpublicized "feature" of the Dell laptop and bios).

    Read this first and save your $$ on batteries, etc.... <sigh>

  • I had my dell latitude D610 for about 6 months (used), after a month it started saying "Cannot recognize charger, insert dell latitude charger", I was able just wiggle the wire it use to wok for a while. Then I wasn't able to do it anymore, it was usable for power only, not charge though. I ended up getting a replacemement that was compatiblewith, because it cost too much to ship to canada. It worked for about 4 months, lately it has been not recognizing the charger and there are flashing lights 4 quick flashes then one green flash but it doesn't charge the battery. I tried checking the where the hard drive making sure it was secure funtioning properly, it worked last. I am unable to check the BIOS because I didn't get a manual, I am not computer guru. I am thinking it's not the charger. Both my charger are doing the exact same thing.

  • i have happily had no further probelm since it was repaired under the warranty - I have paid for an extended warranty though

    certianly if this happened to me i woud try the sugestion posted above to power off completely including the back up power and see if that resets everything?

    please let us know either way if this works for you?


  • I have had the computer off while charging. I took it in to see if it was the adapter or the battery or the computer turned out it was the battery. Put a a different battery in the flashing light are gone, so I guess I will have get another battery. I guess this is what I get for trying to save a few hundred bucks for buying used. I hope everyone can get they're problem resolved as well without having empty they're pocket book.

  • I too bought a used D610, and battery wasn't charging, not discharging.  Shame on the .com company that sold me this - I'm sure they knew it had this problem.  Is everybody out there just to make money and the "heck" with the consumer?  Bought a new battery thinking it was the battery, but it (of course) didn't solve the no charging problem.  Then I read these postings (thank you) all the way through and felt I should reply.

    1.   Tried removing the coin battery - except mine was located in the modem compartment, not the main battery trap door.  Removed it for 30 seconds and it prompted me for the new date and time, but didn't fix the charging problem

    2.  Removed the coin battery for 30 minutes and this time it DID NOT prompt me for a new date and time, the correct date and time were still showing.

    3.  Removed the coin battery for about 6 hours and same result as (2) and still no charging.  (How does the computer maintain the date and time after over 6 hours of no battery?  Is there ANOTHER secret battery, or capacitor, or I'm in the twilight zone???

    4.  Tried the adapter from my Dell M90 laptop from work, and still no charge, no discharge.  (The fact that a major technology company, and many others, uses Dell equipment exclusively for the past umpteen years bothers me.  I bought Dell because I was impressed by the performance of these at work.  Guess I need to rethink.  But I won't buy HP thank you!)

    5.  I am an engineer and could do the fix of moving the dang chip from the charger to the computer but now I'm wondering if even that will work.

    6.  Obviously Dell has no clue - I'm hoping they wouldn't be screwing us on purpose.  But some poor engineer at Dell does have a clue - I assure you!



  • I have been having the same problem with my D610 for several months. "Warning: An unknown AC power adapter has been detected, > preventing optimal system performance. Strike the F3 key (before the F1> or F2 key) if you do not want to see power warning messages again." I have tried replacing the battery, replacing the charger, and searching the forums for a solution but without success.

    Finally, earlier today, I saw a post over at FixYa from warnakula that suggested updating the BIOS. I downloaded and reinstalled the latest BIOS from Dell, even though it was the same as the version that I was already running, and now everything seems to be working. The battery is charging and no power supply warning on startup.