Latitude AC Adapter Issue

I have the same problem with my latitude C840.

I contacted Dell helpdesk but this is not a known issue.  I tried four AC-adapters and all of them stops supplying power to the laptop at a short time. Also the AC Adapter light goes out.

They replaced a powersupply-card in the notebook on 27th of oktober. So far no problems.

Message Edited by Hulta01 on 11-22-2002 07:32 AM

I have the same problem, returned from Xmas break and the power adaptor of my docking station was still active, docked my C800 laptop now the green LEDs keeps powering off. Opon re-powering the power cord on the adaptor the adaptor then powers up for about 5 to 10 mins.

Something on the OS must be causing this, I am running WinXP.

We have about 100+ C800's out of our shop and a majority of our systems have this same problem. As said before, Dell denies this is a known issue. Dell support told me to update the bios. This did nothing except take the machine out of our testing compliance .

The trick we found was to unplug the adapter from the laptop, boot it and wait a few minutes. Then plug the adapter back into the back of the laptop making sure the adapters green light is on first. This seems to hold the power on.

If anyone finds anything else more permanent of a fix, please let me know.

I'll add my concerns, we have 12 of these c840's four have had this problem.  I am currently trying to diagnose one that began last week (green light on power supply goes off after a few minutes, laptop starts running off of battery instead).  According to user happens docked and undocked.  I have tried swapping power supply, docking station, battery, and updating the bios to A06.  A workaround I found that the users do is to remove the battery altogether, thereby forcing the laptop to run off the AC power.  I'm starting to think there may be a defect in the software load from Dell. Any opinions from others experiencing this are appreciated. 

All,

Thank you for using the Dell Community Forum.

If you continue to have problems where the AC adapter seems to shut off, then please contact Technical Support.

I have the same kind of issues with my Latitude C840, but it's even more weird. First, the laptop switchs from AC Power to battery even if the power cable is plugged. My first guess was that it is an adapter or cable issue but this is not the case as I am unable to boot from the internal battery (although the load is 100%). So I need to boot from AC power, then the labtop switch automatically to internal battery (after a few seconds) and when I remove the cable, the labtop switches off !! (this is the weird part of m problem). I must add that the green LED on the external adaptor is always on. 

This is not an OS issue as I've a dual boot with Windows XP Pro / Linux Mandrake 9.0 and I get the same behaviour with both OS's. In my opinion, either it is a BIOS issue (but I won't take the risk to change the BIOS as an outage during the upgrade could definitively crash the machine) or it is a Quality Assurance issue with the motherboard.

I haven't called Dell yet but when I read this message board, I suprised they are not aware of this issue.

My 0.02,

Thierry

>> This is not an OS issue as I've a dual boot with Windows XP Pro / Linux Mandrake 9.0 and I get the same behaviour with both OS's. In my opinion, either it is a BIOS issue (but I won't take the risk to change the BIOS as an outage during the upgrade could definitively crash the machine) or it is a Quality Assurance issue with the motherboard.

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Could be a corrupted BIOS? From memory there's a 'Restore Defaults' type entry somewhere in most BIOS programs, but I can't check the options on my C840 while I'm typing this.  If you can find this option it should be safe enough to try, the danger with power fail is a reboot part-way through writing the complete BIOS program - not just changing the settings on existing program.

Agree about the risk of flashing the BIOS with your weird symptoms.  I'd call Dell's phone support mention your concerns, and have the tech advise and instruct... that way you know where to sue if it fails.

Another thing worth trying might be to disable all power management in the BIOS setup screens.

Reading your msg again, you might even be looking at more than one defect. If you can test your battery and PSU on another C840 and/or borrow a known good battery and PSU for testing it would be worth a try so you can give TS the full picture when you call. Make sure the PSU brick is the 90 Watt PA9 series, not the 70W model from a lesser laptop.

My C800 running BIOS A21 and Win2K has experienced this problem intermittently.  Just checked and I have the PA-6 series adapter (70W).  Overheating seems a likely cause, since I generally keep two batteries installed and this problem occurs most often when they are pretty low on charge.  If the charger shuts off, I pull one battery for a while, reset the charger (disconnect and reconnect) and usually have no further problems. 

The deep discharge is usually because the system self-started from a Fn-Esc "Suspend" and drained itself while it was in my bag.  Haven't solved that problem yet.

Rick, this is good info which tends to support the overcurrent/overheat theory.

I've never experienced uncommanded de-suspend, but I have noticed a few occasions when my old notebook (CPxJ) failed to suspend on closing the lid or hitting the button.  Weird things in memory suspected, a reboot always seems to fix it. The only things which come to mind to trigger return from suspended condition are that something snagged the lid latch in transit, or you have an intermittent defective lid switch (will be a PITA to diagnose).