Removing keyboard and memory on HP Compaq nc6400

posted in: 3. Compaq & HP | 67

In this guide I’ll explain how to remove the keyboard and replace the internal memory module on a HP Compaq nc6400 series laptop.

HP Compaq nc6400 has two memory slots. One of them can be easily accessed from the bottom but the second one is hidden under the keyboard. In order to replace the internal module you’ll have to remove the keyboard.

First of all, turn off the notebook, 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.

HP Compaq nc6400



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.

Unlock keyboard

Now you can lift up the keyboard as it shown on the picture below.

Be careful, it is still attached to the motherboard.

Lift up keyboard

It is possible to remove and replace the internal RAM module WITHOUT disconnecting the keyboard.

Carefully slide the keyboard aside and access the RAM slot.

I show how to disconnect and remove the keyboard only for readers replacing the keyboard.

Place the it upside down on the palm rest. You will find two flat ribbon cables connected to the motherboard.

Keyboard cables connected

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.

Open keyboard connectors

Now you can remove the keyboard and replace it with a new one if necessary.

Remove laptop keyboard

On the picture below you can see the hidden RAM slot.

Carefully push on two latches pointed with red arrows until the module pops up at a 30 degree angle.

Pull the module from the slot by the edges.

Remove laptop memory

HP Compaq nc6400 is upgradable to 4GB maximum.

You can install up to 2GB RAM module into each slot.

Use DDR2 PC2-5300 667MHz SODIMM RAM.





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67 Responses

  1. Thank you for this information. Without this information, I don’t think I’d have been able to upgrade the memory successfully.

  2. yeah thank you– a little tricky, this helped loads

  3. Emery Jordan

    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?

  4. IML Tech

    Emery Jordan,

    Got any Ideas as to what happened or did not happened. I am supposed to configure the upgrade in the bios?

    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.

  5. 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.

  6. IML Tech

    Matt,

    This was helpful. One minor change. In the first picture you list the keyboard screws, well the rightmost screw is not correct.

    Thank you, I fixed the picture.

  7. 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.

  8. IML Tech

    peili,

    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?

    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.

  9. 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!

  10. tanstaafl

    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.

  11. 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.

  12. IML Tech

    Mark,

    I added a 2GB stick in the external compartment and rebooted. System properties shows 1 GB of RAM still – should be 3 now.

    Make sure the second (2GB) memory module is installed correctly. Try reseating the memory module.

    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?

    Nope, it should be recognized automatically.

    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”.

    I don’t think this problem is related to your new memory.

  13. 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

  14. Princip

    How do you keep this site up? Its awesome! :)

  15. IML Tech

    Princip,

    How do you keep this site up? Its awesome!

    I really enjoy doing that. It’s my hobby. :)

  16. simon

    is this similar to replacing a keyboard on a hp compaq 6735s if not could you help me plz

  17. IML Tech

    simon,

    is this similar to replacing a keyboard on a hp compaq 6735s if not could you help me plz

    I have a different disassembly guide which covers HP Compaq 6730s and 6735s notebooks.

  18. Lou Ann

    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.

  19. 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?

  20. Michael

    Cool instructions! Took me 5m to repalce my memory

  21. 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.

  22. 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?

  23. IML Tech

    John,

    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 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

  24. IML Tech

    Sjors,

    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.

    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.

  25. 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? :)

  26. 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 >>>>>>>

  27. Rob,

    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.

    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.

  28. 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.

  29. IML Tech

    RobF,

    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.

    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.

  30. 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?

  31. fred wilson

    To short tempered human beings, if your keyboard on your nc6400 gets full of dirt, it will go crazy when you type a letter, and that letter will repeat over and over until your blood pressure hits the stratosphere. When you try to type a sentence, a sentence of unintelligible jumble types itself, looking like a language from another planet. This time your blood pressure soars beyond the limits of human restraint, and you do what? You slam your fist into the keyboard in an uncontrollable adrenaline-induced rage. This next sequence of events will shock unconditioned beings, so brace yourselves. The battery flew out of the bottom, and the plastic top cover latch flew across the room! Luckily, the battery went back in and snapped into place perfectly, and the plastic latch snapped back into place unharmed. No harm done. Except! My keyboard is bent inward now, and a few letters are lower than they should be. It works fine though, and I literally got away with the attempted murder of an HP nc6400 that rightfully deserved a good beating.
    Everyone has wanted to viciously attack a computer before, and I hope you vicariously enjoyed the experience through me.
    Now, i shall use your wonderful keyboard removal instructions to remove said keyboard, and push the dents out from underneath, and hopefully all my letters will be even again.
    A court of law would ask if I had remorse, and I would tell them to go take a flying leap into Hades. Computers need beating from time to time, and everybody knows it.
    As Edgar Alan Poe said in “The Tell Tale Heart,” …..”Do you fancy me Mad?”
    With your instructions, I am sure I can fix it, or at least improve it dramatically.
    Not that I need one, but how much does a new keyboard cost?
    Finally, I am not going to confession for this sin. If my laptop wants to go for its sin of driving me crazy, then it can find its own ride to church. Maybe the priest can beat some sense into it.
    Thank you immensely for your help. I will do the RAM upgrade when I get rich.

  32. IML Tech

    fred wilson,

    With your instructions, I am sure I can fix it, or at least improve it dramatically.
    Not that I need one, but how much does a new keyboard cost?

    A new keyboard for HP Compaq nc6400 could be found on eBay for less than $20.

  33. fred wilson

    Thank you so much your your removal procedure. It worked perfectly. I had to peel back some of the plastic backing, and push my dents out with a screwdriver. Got all my letters even. Plenty of adhesive left on the backing too, so i didn’t have to reglue it. Keybord is even and works perfectly.
    How much do the 2 gb ram sticks cost for this nc6400? I’m anxious to upgrade.
    When i move up to 4 gb ram, specifically what differences in performance will i see?

    OH, and thanks so much for your procedure. It’s rewarding to have done this with your help.
    I’ll stay in touch with your site. It’s very good. I’m a devoted follower now, and look forward to my next project.
    Thanks Again,
    Fred

  34. IML Tech

    fred wilson,

    How much do the 2 gb ram sticks cost for this nc6400? I’m anxious to upgrade.

    It depends where you buy it.
    If you are not in a hurry, I would suggest buying online (no tax, free shipping :) ).
    Just google 2GB DDR2 PC2-5300 667MHz SODIMM and you’ll get an idea how much it is. I would say you can get it for about $30-40.

    When i move up to 4 gb ram, specifically what differences in performance will i see?

    If you are running Windows XP, most likely you will not see much improvement unless you are running some very intensive applications. XP will not see more than 3GB anyway.
    But if you are running Vista, it will run better.

  35. Thanks very much. Your clear instructions helped me upgrade the memory on my kidm 514 Mb to 2 GB. They are now getting in to trouble much faster. Cheers MJE :-)

  36. Hi,

    Thanks for the instructions, very helpful.
    One question:
    Systeminfo on my NC6400 tells me I have 1 GB installed memory. Can I just buy one 2GB module to upgrade to 3 GB. Or does it need to be an equal duo, in other words, the same amount of GBs in each slot? I read this somewhere but not sure if that is right. If it is true I would have to buy two modules in order to upgrade to 3 GB, instead of just one module.

    Thanks

    Ronald

  37. IML Tech

    Ronald,

    Systeminfo on my NC6400 tells me I have 1 GB installed memory. Can I just buy one 2GB module to upgrade to 3 GB.

    Yes, you can.

    Or does it need to be an equal duo, in other words, the same amount of GBs in each slot?

    Nope, it’s not necessary.

  38. hi, i wish to upgrade my nc6400 processor. how to remove the processor frm the laptop? is it same instruction?

  39. pchallak

    Instructions have been really helpful. I had accidently spilled some coffee on my laptop and have used these instructions to replace the key board

  40. I purchased 4gb of ram and installed it no problems. But it is only showing that i have 2gb installed.

    Before i changed it out it said i on had 512mb but there were 2 x 512 sticks installed, any idea what would cause this?

  41. IML Tech

    steve,

    I purchased 4gb of ram and installed it no problems. But it is only showing that i have 2gb installed.

    Before i changed it out it said i on had 512mb but there were 2 x 512 sticks installed, any idea what would cause this?

    Maybe one of the memory slots is bad.
    Remove memory modules one by one. Try starting the laptop with only one memory module in place. Try different slots. This way you can find the faulty slot.

  42. Friend is like you have the reference of the Integrated Circuit 8-pin is the IC PU25, located below the keyboard. under that black plastic and the modem card.
    Laptop: HP Compaq NC6400
    I thank you.

  43. Steven

    Thanks for this post! Followed the instructions to get to the fan to clean it – my system runs a lot smoother now.

    But… I have the same problem as Rob in post 26. It seems to me that the back light is simply not switching on when booting with the AC cable attached. That is annoying, because I can’t leave the battery out when I have to work a few days form a desk (which I normally do to save the battery).

    Is there any news on this issue?

  44. Mike N Tara

    Thanks, this was helpful in removing keyboard and installing 2GB RAm. Grealy appreciated.

  45. Andrew

    Hello,
    I have the same problem like cesar. I’ve destroyed the IC PU25 (Integrated Circuit 8-pin), located below the keyboard. under that black plastic and the modem card.
    Doesn’t somebody know what circuit is it? I want to replace it.
    Laptop: HP Compaq NC6400
    Thank you.

  46. Thanks for the help. The instructions were simple, clear, and easy to follow.

  47. Flemming Hoyer (DK)

    Fred Wilson mentions adhesive and reglue. Does that mean, that I can’t clean the keyboard underneath. I have the same problem with letters, typing themselves and would like to clean the keyboard.

    Thank you for a fantastic site.

  48. IML Tech

    Flemming Hoyer (DK),

    Fred Wilson mentions adhesive and reglue. Does that mean, that I can’t clean the keyboard underneath. I have the same problem with letters, typing themselves and would like to clean the keyboard.

    Nope, you cannot clean it.
    You need to buy a new keyboard and replace it.

  49. Hi, I just got a HP Compaq NC6400 PK130060200 for my laptop but when i decide to change it i realise that mine is PK130060100 and the ribbon that connect the system board on it is much narrower and the one i got PK130060200 is much wider so i can’t insert it to the ZIF connector.

  50. Hello,

    “Fred Wilson mentions adhesive and reglue. Does that mean, that I can’t clean the keyboard underneath. I have the same problem with letters, typing themselves and would like to clean the keyboard.”

    Solution is easy: nc6400 has an issue which cause this behaviour, All You have to do it put sheet of paper under keyboard. It works for me and i like my laptop again :-)

  51. Hi. I had 1 GB of ram in my laptop (2 x 512mb), and when I got a 2gb ram stick and replaced one of my 512mb sticks, I was expecting either 2.5gb of ram or 512mb of ram. I actually got 1gb again. I have tried both slots and got the same result. Any ideas?

  52. AAUGH!! I broke the ribbon cable retention tab!! The larger one. Can anyone recommend where I can get a replacement?

  53. IML Tech

    @ Fred,

    I broke the ribbon cable retention tab!! The larger one. Can anyone recommend where I can get a replacement?

    Is it broken really badly.
    Here’s something to try.
    Insert the cable back into the connector. Place the retention tab back in place the way it should be. Secure connection with sticky tape.

  54. hi
    how can proceed to put back ribbon connector for Fujitsu LifeBook S7020 keyboard? it’s driving me crazy!!
    thanks in advance

  55. Dear IML Tech,

    Currently I have 2 * 512 MB RAM. I will upgrade to 4 GB.

    What would be the difference between the following options?

    512 MB + 4 GB – in this case I wouldn’t have to take apart the laptop; I would have to change only the easily accessible panel
    4 GB – I would take out both modules and insert only 1 piece of 4 GB module
    2 GB + 2 GB

    Any of the above would do? Would the end result be the same?

    Thanks,
    Arpad

  56. IML Tech

    @ Arpad,

    I doubt that this laptop can support 4GB RAM module in one slot.
    I think your only option would be installing two 2GB RAM modules.

    512 MB + 4 GB probably will not work at all. Laptop might start properly but will not see all memory.
    4 GB probably will not work at all.
    2 GB + 2 GB I think the only option.

  57. Mark Mann

    This particular laptop will not support DDR3 Ram (4GB Module). You will need 2 2GB DDR2 modules to obtain 4GB

  58. ahchandio

    dear,
    IML Tech
    1. iam having this machine hp nc6400, can i use my PCMCIA OPTCL broadband in pakistan please guide me in this reagard.
    2. how can I replace his battery and also how can I use its SC SLOT located right side of the machine.

  59. I have same machine working on IGB ram.I have purchased 2gb memory stick.I cannot get the computer to boot and the graphiocs arent clear with lines on a reduced screen .what can I do?

  60. Can anyone tell me how to replace the motherboard on this unit

  61. IML Tech

    @ tim,

    Check out the official service manual for HP Compaq nc6400 notebook. The manual has step by step disassembly instructions.

  62. CAD User

    Thanks for the pointers. They are helpful. Cheers!

  63. gafurr

    HP Compaq 8710w Mobile Workstation I put another adapter and there is no ignition have the opportunity to tell a burn any part or otherwise has not done smoke no noise became

  64. hi,

    Thanks for the ” Tips . Pictures and careful removal ideas and guidance”
    of hp nc6400 laptop, which are very much useful and I can’t find these even in hp site.

    Once again Thank you Sir.

  65. The Defenestrator

    Tankee kindly.

  66. Shishir

    Hi,

    First i thank you guys to keep such a great site and extremely helpful
    step by step guide for this DIY. I have a different problem, the screen has become red all of a sudden and it remains same. Please guide me how to cure this.

    Thanks in advance..

  67. IML Tech

    @ Shishir,

    the screen has become red all of a sudden and it remains same.

    If it’s solid red, check connection between the video cable and LCD screen/motherboard. Also, try replacing the cable.
    If the image still present but the screen has a red hue, this could be the backlight lamp or inverter related problem.