I have a Compaq Evo n600c laptop that loses power with no warning when running on battery. By losing power, I mean it doesn't go through the normal WinXP shutdown; the screen goes dead and the indicator lights turn off. This does not happen when running on AC power. I haven't found other reports through search engines of this so I'm turning to forums.
The battery is a new, Compaq brand battery. The battery takes and keeps a charge; XP says it is full, and the power indicator on the top of the battery also shows it is full.
The power losses happen at seemingly random intervals. It can happen with 100% power or 50% power. Generally it happens within the first 10 minutes after the computer has been turned on but has happened as far out as an hour. It happens while in one place on a table and on my lap while on the couch. I don't think the computer is over heating since it happens mostly while the temperatures are still all under 40C, and the fan works. Also, I can immediately press the on button and turn the computer right back on using the battery as the power source.
This is a new install of WinXP Pro. The only programs installed, that aren't installed with WinXP, are Firefox and SpeedFan. The hard drive is also new. The computer starts up and runs fine on battery and AC power (i.e. no error messages). The computer doesn't have problems while running on AC power.
I haven't opened the laptop up yet and am looking to avoid doing that. The connectors look clean and free of corrosion. There is no damage I can see to the battery compartment.
Last edited by geodanny; September 23rd, 2005 at 11:30 PM.
My guess would be an intermittent connection between the battery and the computer. Look at the contacts on the battery, or in the computer if they're accessible. Are they of a type that could be gently bent out to make better contact?
Sounds like a dodgy battery or a dud voltage regulator that the Armada M series was famous for. Got an Armada M700 with the same symptoms, had an earlier one that i replaced the regulator on and it was fine. Another little tip i know of that might help, if the battery is similar to the m700, has it got the test leds/lights? It might be the micro controller on the battery getting stuck, one way to reset is to crack open the battery so that the controller loses power and resets, another way is to let the battery discharge for a few months and lose power. This also sorted a few m700 batterys that others said were plain dead. Btw, was this laptop designed for XP? I might be stark raving mad, but i swear 3 M700 lappys i fixed had problems with power in battery mode just after installing XP for a few weeks, could be a management or ACPI problem.
R.I.P Rangeral, To one of HWC's best moderators and a great guy
By the way, what does BTW stand for?
It is better to be tried by 12, than carried by 6.
Thank you everyone. I will look into testing and getting a new voltage regulator. The battery contacts are all shiny. I have two new batteries and both have the same problem. I know someone else with the same model Evo and my battery in their computer doesn't cause it to lose power and vice versa, their working battery in this computer has the same problem. This isn't a suspend function issue; it is a power failure. I turned off all power management functions in the BIOS and OS.
Compaq/HP refers to this part as a DC-DC Converter Board. The N600c needs part number: 241435-001.
I've been slow to act, but I'll be ordering the part this week and installing it next week when I get some time. I'll post again to let you know if I'm successful or not.
Incidentally, my work laptop crapped out this morning with the same issue. It is an HP compaq nc6000. My hard disk was put into a new shell and the problem disappeared. Talking to other coworkers, it sounds like most HP and Compaq model lines have this problem (Armada, Evo, and NC6000). We've been using Compaq/HP computers almost exclusively over the past four or five years and it is a recurring IT headache. It is always amazing when several people share a 'me too' moment when hearing about a computer hardware problem.
I calibrated the batteries. That didn't work. I also replaced the DC-DC converter board. No luck there either. I'm assuming the replacement board isn't a dud. I checked the battery connections while I had it opened up and that didn't see any problems there either.
Anyone know of a good logging program that would let me log the power input based on source? Anything open source or free is preferred but I'll pay if I need to. I'd like to see if there is a gradual decrease in power or it is cut off. At this point, I'm assuming this may have something to do with heat expanding a joint or connection to a cause power disruption.
In the end, I might give up and only use this laptop with an AC source. At least it still works using AC. I'm using it right now. I can run it for hours using AC but less than 5 minutes on battery power.
By replacing the shell for my work laptop, I mean they pulled my hard drive out of the bad computer and put it in a different one. It stayed in the same caddy because the replacement laptop was the same model.
P Elliott: You'll need to get a T-7 size torx wrench to get open the computer (they sell them with screwdrivers at most tool stores like sears). I assumed that I could get by with a flat head screwdriver because the outer screws have a slot as well as torx head - I was wrong.
I have alsoCompaq Evo n600c laptop which also loses power with out warning when running on battery.
I am using WINDOWS XP PROFESSIONAL. I have found, if i run the computer in the windows xp safe mode on the battery the laptop working fine and giving 2-3 hours backup time. Whin i run the laptop again in the normal mode of windows xp i am facing the same prolem.
geodanny please check your laptop in the safe mode.