HomeIn this guide I’ll explain how to remove the keyboard and replace the internal memory module in a HP Compaq nc6400 series laptop.
HP Compaq nc6400 laptop has two memory slots. One of them could be easily accessed from the bottom but the second one is hidden under the keyboard. In order to replace the memory module in the internal slot you’ll have to remove the keyboard.
First of all, turn off the laptop, unplug it from the power adapter and remove the battery.
There are three screws securing the keyboard on the bottom. You can remove these screws with a #8 torx or flathead screwdriver. Remove all three screws.
There are four small latches located in the top row of keys on the keyboard. Unlock all four latches by moving them down with your fingernail.
Now you can lift up the keyboard as it shown on the picture below. Be careful, the keyboard is still attached to the motherboard.
It is possible to remove and replace the memory module in the internal slot WITHOUT disconnecting the keyboard. Carefully slide the keyboard aside and access the memory slot. I show how to disconnect and remove the keyboard only for readers replacing the keyboard.
Place the keyboard upside down on the palm rest. The keyboard is attached to the motherboard via two flat ribbon cables.
You’ll have to unlock both connectors in order to release the cables.
Each connector has a locking tab (one is white and another one is brown) witch has to be moved about 1-2 millimeters up.
Very carefully move both locking tabs up with your fingernails. Release both cables and pull them from the connectors.
Now you can remove the keyboard and replace it with a new keyboard if needed.
On the picture below you can see the hidden memory slot.
Carefully push on two latches pointed with red arrows until the memory module pops up at a 30 degree angle. Pull the memory module from the slot by the edges.
HP Compaq nc6400 laptop is upgradable to 4GB maximum. You can install up to 2GB RAM module into each slot.
Use DDR2 PC2-5300 667MHz SODIMM memory modules.
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October 16th, 2009 at 12:58 pm
Nice step-by-step guide. The questions / issues i have are as follows:
Issue
I currently have 2 gigs (1x 2 gigs) sticks in my latop. I was told XP only recognizes up to 3 gigs.
Question
1) If i use one 1 gig and one 2gig stick = 3gigs, will that affect performance of the box? Can this be done without issues or i have 2 run the same in parrallel?
2) Even though the machine can take up to 4gigs, does it use all 4 or 3gigs, since XP / The machine recognizes and shows 3 Gigs?
October 9th, 2009 at 7:44 am
RobF,
Thank you for your comment. You are correct, it is possible to replace the memory module without disconnecting the keyboard. I updated my instructions. You’ll see it under the third picture.
October 9th, 2009 at 1:18 am
Thanks for the information. I found this trivially easy to do without disconnecting the ribbons. Given the problems people reported doing so it might even be worth updating the article.
September 22nd, 2009 at 9:56 pm
Rob,
If you get this failure with a known good AC adapter, most likely it’s related to the motherboard. Sorry, cannot point you to the faulty component. I don’t work on component level.
September 22nd, 2009 at 4:12 pm
I have a Compaq NC6400 that runs fine off battery but with adapter plugged in, will not power up (with or without battery installed). I also tried docking it hoping that it was maybe a faulty power receptacle on the back of the laptop, and get same results. Proper adapters, etc – just blinky blink yellow charge light.
Can charge battery in another laptop, swap it out and all is fine.
Please help >>>>>>>
August 14th, 2009 at 1:13 am
I am having a slightly different issue, but it’s about this laptop, sooo..
My screen has a 1 in 100 chance of turning on. Most of the time the screen will be completely dead, but very, very rarely, the computer works perfectly, so it’s not an actual dead screen. I surmise that the connector to the motherboard is loose, but for the life of me I can’t find it. Advice?
June 24th, 2009 at 1:33 pm
Sjors,
That’s true. It’s not necessary to disconnect the keyboard from the motherboard in order to replace or upgrade the memory module. Simply flip the keyboard over on the palm rest.
June 24th, 2009 at 11:03 am
John,
Are you using PC2-4200 DDR2 SDRAM SODIMM module?
It could be bad connection between the memory module and slot, incompatible memory module or bad memory module.
If the module fits into the slot without any problem, you are using a DDR2 module and it should be compatible.
Try installing the same module into the slot on the bottom and test if it works. If not, probably it’s a bad module.
Try installing the same module into the same slot again, maybe you didn’t connect it properly the first time.
If the new module doesn’t work
June 22nd, 2009 at 8:27 pm
Your instructions were great. I added 2 mb to the bottom memory slot, when I put it under the keyboard. My computer came on but no screen. I put back the old memory under the keyboard and it works again.
Are all memory sticks the same, as long as you fit it in the wave of the slit?
June 18th, 2009 at 12:29 am
I found out that you can just lift the keyboard and when your carefull you can replace the memory without having to disconnect the keyboard.
June 11th, 2009 at 3:11 pm
Cool instructions! Took me 5m to repalce my memory
June 10th, 2009 at 7:59 am
This is a good instruction. I am really looking to open the whole PC. I bike to work and my CD drive came partially disconnected and the PC will not boot. I know that i just need to connect it, but I cannot figure out how to get to it. Any suggestions?
June 8th, 2009 at 6:01 am
Your instructions were quite helpful, yet I could only figure out how to replace the 1 GB memory. I could not see where the other memory slot was and am wondering if I was doing something incorrectly? I am going to take my laptop to the electronics store where I purchased the 2 x 2 GB and figure out if I can install the second 2 GB memory card on my HP nc6400 notebook. The improvement with VMware and MS Office 2007 is huge with the upgrade to 2 GB. If you have any ideas of what to do for the second card, please reply. Thanks.
May 25th, 2009 at 4:25 pm
simon,
I have a different disassembly guide which covers HP Compaq 6730s and 6735s notebooks.
May 22nd, 2009 at 7:34 am
is this similar to replacing a keyboard on a hp compaq 6735s if not could you help me plz
April 20th, 2009 at 10:32 am
Princip,
I really enjoy doing that. It’s my hobby.
April 20th, 2009 at 10:24 am
How do you keep this site up? Its awesome!
April 11th, 2009 at 10:35 am
Hi,
I managed to upgrade with these clear instructions, but also broke one stem on each clip. Is there anywhere i can buy these clips?
Thanks Rob
April 7th, 2009 at 10:31 pm
Mark,
Make sure the second (2GB) memory module is installed correctly. Try reseating the memory module.
Nope, it should be recognized automatically.
I don’t think this problem is related to your new memory.
April 6th, 2009 at 4:08 pm
I added a 2GB stick in the external compartment and rebooted. System properties shows 1 GB of RAM still – should be 3 now.
I vaguely recall adding memory to a desktop and having to reset something in BIOS to recognize the added memory. Do I have to do that here?
Finally, since adding the RAM module, when I click on Workstation Info on my desktop I get the Warning message “Unable to access the N: drive, please check your network connectivity”. Huh?
Any help would be greatly appreciated.
March 14th, 2009 at 3:41 pm
As Randy says, be VERY careful with the little clips that secure the ribbon cables. I broke one (even though I was being careful) and now the trackpoint nub does not work on my keyboard. I regret the entire process, and should have just been happy with the ram that I had already installed in the slot accessible on the bottom of the computer.
March 8th, 2009 at 7:38 pm
Your info saved me a lot of grief. HP instructions are no where near as well organized or as easy to follow as yours. Thank you so much for supplying this.
I did have one problem unplugging the ribbon cables. Those cheap little clips both broke on one side. My son, who works on computers all the time, helped me and he even broke one. They are VERY fragile. I put them back to hold the ribbons and will try to buy some replacements. They are working so far.
Thanks again!
January 13th, 2009 at 9:55 pm
peili,
I’ve searched HP website for a manual for your laptop and couldn’t find any. If your laptop should have 2 RAM slots, but you can find only one on the bottom, most likely another slot is located under the keyboard.
The keyboard removal steps are the same for most HP Compaq laptops. Check out Compaq and HP laptops category on the right side of the website. I’ve published many guides for different HP laptops in there.
January 12th, 2009 at 10:04 am
Your website is really very helpful. I have a better idea on accessing the internals of my own laptop.
I have a Presario X1439AP. I should have 2 RAM slots. One of the RAM slots has its own compartment and is directly accessible from outside without dismantling anything. I cannot find the other RAM slot. Is it under the keyboard? How do I get access to this? Any help is much appreciated.
November 26th, 2008 at 11:30 am
Matt,
Thank you, I fixed the picture.
November 26th, 2008 at 11:22 am
This was helpful. One minor change. In the first picture you list the keyboard screws, well the rightmost screw is not correct. The circle should be around the one directly left of the one you got circled.
November 19th, 2008 at 11:23 am
Emery Jordan,
You don’t have to configure the BIOS. The memory stick should be detected automatically.
Make sure the new memory module is seated properly, all the way down into the memory slot. Try reconnecting the memory module.
Also, try installing the original 512MB back and booting the laptop. It’s possible the new memory module is defective.
Most likely it’s just not seated correctly.
November 19th, 2008 at 11:17 am
Your information is clearer then the official site for HP on this issue. However, when I inserted a 1 GB stick (having replaced a 512MB stick of the same speed 5300), nothing happened when I turned the machine on–no booting up nothing.
Got any Ideas as to what happened or did not happened. I am supposed to configure the upgrade in the bios?
November 3rd, 2008 at 11:20 am
yeah thank you– a little tricky, this helped loads
October 27th, 2008 at 6:41 am
Thank you for this information. Without this information, I don’t think I’d have been able to upgrade the memory successfully.