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CGDobyns
Silver

Dell Latitude D600 - AC Not Charging Battery

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).

133 Replies
husky0894
Platinum

Re: Dell Latitude D600 - AC Not Charging Battery

The power jack has likely come loose from the mainboard.  Replace it IF you have the tools and expertise (it's multilayer-board soldering).

 

CGDobyns
Silver

Re: Dell Latitude D600 - AC Not Charging Battery

Okay, that sounds somewhat reasonable, and I'm certainly willing to crack open the case and take a look at the power input jack assembly and heat up my soldering iron.  I guess I'm less clear on why I would want to replace it, if it has only just come loose from one of it's connections.  And I'm likewise ambivalent (ambivalent = skeptical), that the rest of the laptop would be still be getting AC power, if a connection had separated, through repetitive movement / stress fracture (my power plug connector seems to be firmly anchored).  I would have thought that the power supply routing that carries voltage to the entire laptop would be routed to the battery to recharge it in parallel, just like the battery shifts to discharge when the AC power is removed.  I guess I can get in a check with a continuity test for broken connections.

Anybody else want to weigh-in?

BobL55
Silver

Re: Dell Latitude D600 - AC Not Charging Battery

I've had two similar problems with a D600. Both times it was dioagnosed as a motherboard fault (after 2 and 4 years), changed once under warranty and on the second occasion it cost me serious cash. I'm not sure whether this really was the problem or whether it's the stock remedy for similar faults. I was told by the 'engineer' on the first occasion that D600 boards were prone to failure.

CGDobyns
Silver

Re: Dell Latitude D600 - AC Not Charging Battery

As a follow-up to this posting, I elected to take a slightly different approach to a solution and while I didn't arrive completely at my destination, the trip has at least been fun and informative. 

First, I saw no obvious signs of any failure on the AC power input assembly, but instead of searching for a new motherboard or breaking out my soldering iron, I canvassed eBay and managed to find a replacement (used) D600 base unit, which, while stripped down of mostly all its components did have a faster 1.6GHz speed processor, so I figured that for the $50 that it eventually cost me, it was a good investment to rule out the motherboard problem and the AC power input assembly issue. 

Swapping out the components (screen, keyboard, DVD/CD drive, memory, wireless transmitter and hard drive) literally took ten minutes, and the unit powered up with no apparent problems.  However, the same battery charging problem still persisted (AC adaptor not recognized) by the system.  That almost has me wondering if the AC adaptor is somehow the culprit.  I'm pretty sure by some fluke coincidence it can't possibly be both batteries (one of which still is carrying a charge), since they were both working fine before this problem occurred.  So barring a higher level problem with the power supply to my entire house, that has to only leave a problem with the AC adapter or a software problem?  I've never heard of a software problem like that, but let's not rule it out. 

The thing I noticed is that I've got a PA-12 Family adapter, which is obviously powering the laptop just fine.  But I see that there is also a PA-10 Family adaptor, which is also shown as being compatible with the Latitude D600 computers.  The only difference in the specs that I see is that the PA-12 has a rated output DC of 19.5V at 3.34A and 65Watts and the PA-10 has a rated output DC of 19.5V at 4.62A and 90Watts.  I will conceded that this is where my electrical knowledge begins to get thin.  The differences in those DC outputs couldn't possibly be the problem, could it.  Especially, when the PA-12 was obviously doing the job (previously).  Anyone have any further thoughts on any of this, up to this point?

CGDobyns
Silver

Re: Dell Latitude D600 - AC Not Charging Battery

I love it when I get to answer/reply to my own postings, but I thought I would build on the posting based on some additional research I've done. 

Okay, it appears that the PA-10 unit was produced primarily to power the Latitude D600 docking station unit.  That accounts for the differential power output (I guess).  The PA-12 unit is produced principally to power the Latitude D600 laptop alone.  So, the PA-10 is downwardly compatible to the laptop alone, but not the converse, as the PA-12 apparently does not have sufficient output to power the docking station. 

While this is all good information, I'm not sure it really answers my primary problem - which I still strongly suspect resides with a problem in the AC adapter.  Still looking for input on this problem.  Takers?

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magendron
Copper

Re: Dell Latitude D600 - AC Not Charging Battery

My daughter’s 18 months old  XPS 1330 started to do the exactly the same last month.  I have ordered a new battery ($ 200 Cdn) but it didn’t solve the problem.  I have upgraded the BIOS to the latest version with no luck.  We’ll try another adapter, from Dell’s retail booth at a nearby shopping center, to find out if this could be source of the problem but I’m getting very sceptical. 

 

I’m wondering if this is not related to some sort of mod (software or hardware) Dell made to its computers’ charging system after the batteries started to explode all over the place a couple a years ago?

 

I must say that I’m now very upset having a $2000 computer that is now only giving 50% of its functionality after a relatively short existence L

 

Please let us now about your findings…

CGDobyns
Silver

Re: Dell Latitude D600 - AC Not Charging Battery

All right, time for another status update.  After the earlier disappointment in finding out that there was probably nothing whatsoever wrong with my Latitude D600 motherboard (1.4Ghz), I was understandably bummed - except for the fact that I swapped out the base unit for a 1.6Ghz processor for only $50. 

Since I know both of my batteries are in good shape (one still in carrying a charge and both Test buttons show the battery is OK), that left me wondering about the AC adapter.  However, a voltmeter showed that the output was right on spec.  I did manage to track down someone at work who had a brand new laptop which used the PA-10 adapter - and his laptop was charging just fine.  Unfortunately, plugging the relatively brand new charger showed no change in the status of my laptop's ability to charge its battery. 

That has me wondering strongly about a software issue.  To the best of my recollection there was virtually no precipitating event that I can recall that would have impacted either my physical laptop (i.e. motherboard) or the AC adapter (no dropping or even movement for that matter).  So, that has me wondering whether there was not some blip in the computer BIOS that has caused the BIOS system to not recognize the AC adapter - and therefore not allow the system to recharge the battery as a result.  I've got to believe that is the only remaining logical source of the problem, and I'm guessing the problem lies somewhere with the battery charging algorithm.  I'm half-surprised that if this is the problem, why hasn't Dell simply generated another BIOS release to address the issue? 

Well, I'll do a little more research and then attempt to apprise everyone how the approach of flashing the BIOS does in terms of mitigating the problem.  Beyond that, I was smart enough to invest in an extended warranty on the new base unit I purchased - so I have recourse to make a claim if the BIOS flash doesn't result in a fix.

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CGDobyns
Silver

Re: Dell Latitude D600 - AC Not Charging Battery

After conducting a little further research and having a reasonably constructive conversation with someone at work, I become reasonably convinced that the source of my problem was indeed by BIOS.  A co-worker indicated that he'd experienced a similar problem, and flashing the BIOS on this computer apparently corrected the problem.

So, I went the route of flashing my BIOS this morning, and while I can report that the process, while somewhat anxiety-provoking, is actually pretty easy and nearly foolproof.  First, a quick tutorial on that for everyone's benefit.  The most recent BIOS updates can be readily downloaded off the Dell website, under Drivers and Downloads.  The "flashing" process is even more simple than the download.  From Windows Explorer or using the Run command, you simply invoke the most recent update (I was shifting from the A12 update to the A16 release), and file self-executes. The application asks you if you want to upgrade your BIOS from ____ to ____, which you confirm by clicking OK (or Cancel).  The application the informs you that it will close all existing applications, restart the computer and flash the BIOS - and then requests a final OK click, before proceeding.  The rest was all transparent, with the BIOS taking just a little longer to process the first time during the Post-Test process.  Windows XP launched and loaded as usual, and as far as I can tell, all the prior BIOS/CMOS settings were all carried over successfully during the update. So mostly, unless the flashing process were inadvertently interrupted by a power failure at a critical moment (which only takes a few seconds as far as I could tell), everything should proceed without any problems. 

Now for the bad news.  Flashing the BIOS apparently had no effect whatsoever on the failure in the battery charging algorithm (at least for me).  I'll concede that I'm in a total funk about this whole affair - since the BIOS update was just about the last alternative that was open to me.  So to recap, I took a leap and purchased a new (used) motherboard (with a faster processor), which didn't fix the problem - and it seems inconceivable that there was a electronic failure in both motherboards. I already know that both the batteries I own are fine.  And I've got the benefit of having used a new AC adapter (it still even smells new), with no apparent impact.  Now I've flashed the BIOS, so absent the residual effect of sunspots or the lingering EMP from the atmospheric nuclear tests of the 60's - I'm not sure what my other options are.   I guess I do have recourse to the extended warranty that I purchased (www.squaretrade.com).  I even gave some thought to reflashing the BIOS to the A12 update, although when I attempted to do that, the application warned that Dell did not recommend reverting to an earlier BIOS version.  So, that's where I am for right now.  Additional updates as they become available.

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Re: Dell Latitude D600 - AC Not Charging Battery

:^/ You mentioned two batteries.  Have you tried swapping them around?  If one is draining no matter which cavity it occupies, then it's the battery that has trouble, even if its indicator lights say otherwise. 

On the other hand, if the battery in a given cavity drains no matter which battery is in there, then there's trouble with that cavity.  Either the leads that send power there, or the controller that sends power to those leads.

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