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Posts: 43
Member Since: ‎10-09-2011
Message 1 of 46 (4,563 Views)

HP HDX18t light up but wont boot. Blinks once

I own a HP HDX18t

Windows Vista SP1

8 Cell Lithum Battery

9600 M GT Graphic

Intel Core 2 Duo Processor P6700 (2.53)

Purchased new online in May 2009.


Laptop lights will come on when pushing power on button and I can hear it starting but after a few seconds lights by capslock and numlock begin to blink.  Sequence appears to be one blink, then about 2 second pause, then one blink again, then it repeats.  I've taken battery out, waited a few minutes and replaced.  I have take battery out, held down power button for 60 seconds, then replaced battery.  I have tried powering on with battery removed.  No matter what I do, it's the same results as stated above.


When ordering I got the graphics card upgrade, but applications that utilize the card crash the laptop in a few minutes from overheating, so I just stopped using graphics intensive applications.  Volume controls stick often going all the way up or all the way down with one momentary press of the button.  Power cord connection has worn out so much that I purchased a new battery charger, but it still fits in loosely.  I had been using the new charge for about a month before today when it wont even turn on.   I was considering ordering the dc power interface that's built into the laptop because even with new batter charger you had to wiggle it just right to get the light to come on showing that it was charging.


All this I can live with or work on later and I only mention it in case it pertains to the major problem of not being able to start the laptop.  Forum searchs suggested that "one blink" indicates a CPU failure, so I'm looking for confirmation on that.


I have a fair amout of experience building desktop PCs from scrach but have not yet attempted repairs or upgrades on laptops.


Any help is appreciated.

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Regents Professor
Posts: 4,523
Member Since: ‎12-28-2009
Message 2 of 46 (4,539 Views)

Re: HP HDX18t light up but wont boot. Blinks once

[ Edited ]

I have worked on the HDX18 series quite a bit buying up old used ones and rebuilding them.


 I am not familiar with the codes, but CPU failure is rare, remove one stick of RAM and see if it will boot up, if not try the other stick. It also sounds like a corrupted BIOS and I have a fix for that too, if it's not too far gone.


 The cooling vents need cleaning out and some new thermal greece applied and possibly some new thermal pads, that should solve the overheating and crashing problems, IC Diamond is great.


 The power plug on the laptop is not part of the MoBo and e-bay has tons of these.


 HP Media Services Library to take it apart.


 A thread from me to help address the volume OSD problems, there are some youtube videos there as well to help get it apart. The most difficult is the speaker cover and the hot key bezel around the keyboard.

Posts: 43
Member Since: ‎10-09-2011
Message 3 of 46 (4,521 Views)

Re: HP HDX18t light up but wont boot. Blinks once

Hi, thanks so much for your post.  I'd love to dig into those other issues I mentioned, but right now I just want to get it powered up.


I tried removing one mem stick, then the other, then both, but there is no change.  Lights on keyboard all come on but after a few seconds it all goes quiet.  If I have a CD in I can hear it access the CD and I have power to eject CD.  Once again the two lights, one by the CAPSLOCK and one near the END-PAGE UP keys blink.  They blink simultaneously for about 1 second, then go blank for almost 3 seconds, then repeat which suggests ONE blink to me. 


Here is where I found the "blink" chart found elsewhere in the forums here.  I'm not certain this chart refers to the HP HDX18t, but perhaps you'll find it useful:

Forum thread name:  Help! Laptop wont start 3-1-2011 by soneta2008


All I did was remove the memory as you suggested, but I'm eager to try something else if you figure it will do any good.  Or, please refer me to other resources for trouble shooting if you have any. To give you an idea of my skill level, I would be very comfortable doing the OSD repairs suggested in the link you provided, although as I said, getting it powered up is the only concern I have right now.


Overheating was rarely a problem except when running graphic intensive games or after it sat for a very long time on a poorly vented surface (bed).  Unless you say otherwise, my assumption is that until I can at least get it to boot there's not much point in addressing the colling vents and new thermal grease.


Oh, and the ebay links were great.  The DC-IN-cable in particular was a great find.  I was having trouble finding it in stock on websites, and the prices were excessive (over $80).


Oh, I had no trouble identifying the Serial Number, but I was surprised I couldn't find an online resource that would translate the serial number into the exact product.  I know I have an HDX18, but I'm not sure if it's 1000 or 1100.  Also, I had trouble logging on to with the username and password I created back in 2009.  I was able to reset my password but they no longer have record of my order.  I even tried searching by order number.  Strange. 


Thanks for your time.  Any more help you can offer is greatly appreciated.

Regents Professor
Posts: 4,523
Member Since: ‎12-28-2009
Message 4 of 46 (4,508 Views)

Re: HP HDX18t light up but wont boot. Blinks once

[ Edited ]

I will contact David PK and ask him where he got that LED code chart in the link you gave me. The laptop in that thread is running an Insyde BIOS so the chart may apply. Each BIOS manufacturer has different codes.


 Are you running the HP Support Assistant program ? This thing runs in the back ground and updates things automatically, like a BIOS update. In your case it probably did just that and because you are having issues with your adapter, it may have caused the BIOS corruption.


 Here is  thread to rescue a corrupted BIOS on all HDX 18 machines.


 In order to try this you must have the adapter plugged in and working properly with out the battery.


 I am thinking that the BIOS tried to update itself and the power fluctuated and caused the corruption. If it was just on battery power at the time, the BIOS update should have detected that and the BIOS update should have stopped. This all assumes that you are running the HP Support Assistant.


 It could be a processor failure, it's hard to say, assuming that it is would require that you disassemble the machine anyway. If your going to do that, then I would fix the adapter plug and use the method I gave you to rescue a corrupt BIOS.


 I don't think the processor is gone, they are incredibly durable and can take allot of heat. It's quite possible that the solder that holds the processor plug in place has failed or the video card has become detached from the MoBo causing this problem. If this is the case you would need a MoBo replacement.


 If this was mine I would solve the adapter problem and get that working 100%. After that I would try my BIOS solution. I took a healthy MoBo that was running an older version of BIOS (F25) and I updated it successfully to F34 ( the most recent version) using the method described in the link. It will either work or it won't.


 As for your model, use this link :


 It doesn't matter as they were all pretty much the same. They all ran Intel processors and NVIDIA graphic cards. There were 4 system boards available and all are interchangeable and run the same drivers. ( the drivers are the same for the GT9600 and the GT130 graphics cards) All the chipsets were all the same on all boards.


 GT9600 with 512MB of video RAM and running DDR2 memory  496871-001

 GT9600 with 512MB of video RAM and running DDR3 memory  506494-001

 GT9600 with 1GB of video RAM and running DDR3 memory      506495-001

 GT130 with 1GB of video RAM and running DDR3 memory        519592-001


 If you want you can go out and buy another processor, but I don't think that will solve your problem. This quad will work.


 I think this is yours here, not a P6700, but a P8700

Regents Professor
Posts: 4,523
Member Since: ‎12-28-2009
Message 5 of 46 (4,499 Views)

Re: HP HDX18t light up but wont boot. Blinks once

David got back to me and the chart was here on the HP support pages.


 We also talked and we both agree that the overheating has thrown a CPU failure code, but there may be other damage to the mother board and the CPU failure code is not accurate. If that is the case it's almost impossible to tell what it is.


 You may need a new MoBo, fix the adapter plug first in the laptop and try my fix for the BIOS, you have nothing to loose.

Posts: 43
Member Since: ‎10-09-2011
Message 6 of 46 (4,491 Views)

Re: HP HDX18t light up but wont boot. Blinks once

Hi, thanks for the help.


I'm 99% sure I disabled HP Assisant at startup.  The laptop uses vista so it was taking a very long time just to go from login to ready-to-use desktop.  In fact, once desktop comes up I'd usually wait about 2 minutes before doing anything or else I'd risk an appllication failing to respond.  I really don't understand the wisdom of having background software automate a bios flash without at least some kind of prompt to the user even if the the power cord was detected as being pluged in.  Even so, the theory that the power could have fluxed or even shut down unexpectedly is possible due to the power cord adapter not consistently staying connected.  My wife uses this laptop a lot so there is a bit of an unknown factor, including the possibility that she shut it down using the button instead of the start menu.  I know I mentioned overheating in my OP, but while apps would sometimes crash lock ups were very rare and I haven't been noticing the latptop getting particularly hot as it has sometimes done in the past.  In other words, overheating has not been a common issue. 


That said, I tried the first method in the flash bios link you suggested.   Unfortunately I don't have a usb flash drive at or under 2 gbs, so I tried it with a 6GB flash drive. I didn't know if "left" meant my left or the laptops, so I tried it in both sides.  I gave it 2 minutes each time with keys held down before giving up.   I can't really get my hands on a 2GB flash drive without buying one, but I'll see what I can do.  No way to make this work with a CD rom or anything?   I'm assuming a 2 GB flash drive is required?


Using the link you gave me and the "product" number I was able to determine that I have a HDX X18t 1200. 


I paid about a grand for this thing just over 2 years ago.  In my experience with building desktops I've found CPUs to be very hardy so I tend to agree with you that wouldn't be the problem and the ONLY thing I'm basing it on is the blinking light.  Makes more sense to trust the opinion of you and David who have certainly had more experience with HP laptops than I have.  


Any ideas how much a new mobo will cost?  I paid almost almost $1000 for this laptop just over two years ago, but considering some of the problems I've already had with it and my disklike for Vista I'm not sure at what point a repair isn't worth it.  I'm not afraid to do the work though.


If the blue light on the side by the DC doc is to be trusted, I'm very confident I can have the power cord in and working 100% when doing future testing.  If that's good enough I think I'd rather wait on order new parts or fixing anything other than what it needs to get it booting up.  Anything I need I'd have to order online.  Why throw good money after bad...  


I'll keep looking for a 2GB USB flash drive, but right now I'm pretty bumbed.  Let me know if there's anything else worth trying.   Whatever happens from here, your kindness and help on this has been outstanding.  Thank you.




Posts: 43
Member Since: ‎10-09-2011
Message 7 of 46 (4,488 Views)

Re: HP HDX18t light up but wont boot. Blinks once

Strange, I just posted a long response and it said "posted" but I don't see it so I'll try again a little more briefly this time.


I don't have a 2 GB flash drive, but I tried the bios flash on a 6GB drive but no luck.  I didn't know if "left" meant MY left of the the laptop's left so I tried it on both sides.  Each time I waited over 2 minutes with keys held down but no change.  I could burn a CD Rom but I'm guessing that won't work?  I'll try to get a 2GB flash drive but I don't have one at present. 


Oh, I'm 99% sure I disabled HP assitant from even starting up with windows and the last time the laptop was shut down it was done correctly.  Also, despite what I said in my OP, I really would not say that overheating is regular problem with this laptop.  That said, I see no harm in trying to flash the bios. 


My only reason for thinking it was the CPU was the blinking light so if you and David don't think that's correct then I'd rather take your advice instead.  I have little experience with laptops and less with HP but the desktops I've built over the years have never had a problem with the CPUs.  Thanks for the CPU links, but do you have any idea how much a new mother board would run?


I checked the product number using the link you gave me and it said I have an HDXT 18T 1200. 


I understand your reasoning on getting a new power cord and I don't mind doing the labor, but I hate to pay for and order a part I may not need if the whole laptop is shot.  If the blue indicator power light by the DC doc can be trusted then I'm sure I can plug the adapter in and have it stay securely in place while I try other troubleshooting.  Overall it's a nice laptop but I've had a few other minor issues with it including not liking Vista and just overall slow performance so I'm really going to have to weigh my options before putting a lot into it. 


I'll try to get that 2 GB flash drive.  Whatever happens from here your help and kindness has been great.  Thanks a ton.


Regents Professor
Posts: 4,523
Member Since: ‎12-28-2009
Message 8 of 46 (4,485 Views)

Re: HP HDX18t light up but wont boot. Blinks once

[ Edited ]

A new MoBo from HP for the 1200 series is 458.57$. That's a bit pricey. Here is the part number for the MoBo 519592-001.

 You can also Google it and there are plenty of third party sellers that have new ones, but I like e-bay. For the most part I have had good luck with them. Used ones are reliable and last indefinitely if they were never abused. The part number for your board is underneath the RAM.


 Here are some choices from e-bay _ not much here with the GT130M, just from China and that's OK since all the HDX machines and parts are made in China anyway, with the exception of the processor which is probably made in Mexico.


 You cam also use a MoBo from a dv8, but you would need the dv8 bottom case, the cooling fan and the 'I" series processor.

I have done this making serious modifications to the HDX bottom case and subwoofer to get the dv8 board to fit. It would have been easier to use the dv8 case.


 In theory any USB memory stick would work, and if it's going to work, it would have started beeping very loud right off the bat and would have shut down all on its own after that.


 Your wife should not be using the start button to shut down, it's not good for the hard drive and some people say that it can actually damage it. If you have another hard drive( you can use the one in the spare bay if you have one), install that and start pressing the f10 key immediately on boot up and see if the BIOS page displays. Usually when the hard drive fails though you simply get a message that no boot device is found.


 Left side meaning the side with the HDMI connection.


 As far as trying other things, I think that's it. It's at the point where I would start substituting parts to track the problem. I have lots of spare accumulated so it's easy for me.


 It will happily run with W7 and even with Vista 2 minutes is too long. My first HDX took around a minute and 10 seconds to boot with Vista.


 I had no HP stuff running in the background and I uninstalled or disabled any bloat ware.


 If the HPSA has been disabled then it's very unlikely a corrupted BIOS problem, I think the board has had the biscuit for what ever reason.


 If this was mine I would spend the money on it, I think the new machines are plain and ugly and the quality of the parts has gone down hill.  HP doesn't make a laptop with an 18 inch screen anymore, but Toshiba still does the last time I checked. There are some available with the second generation "i" series processor in them.


 There is even a 3D one available, but it's not an 18 inch





Posts: 43
Member Since: ‎10-09-2011
Message 9 of 46 (4,477 Views)

Re: HP HDX18t light up but wont boot. Blinks once



Well, new problem.  I can't even get it to power on any more.  Even with it plugged in and the blue light on (battery removed), pushing the power on button only makes it light up for about a second and then it goes dark.  I actually got an under 2GB flash drive but didn't get a chance to try it and given what you said about the beeps there doesn't seem to be a point.  As I recall, the wireless and volume indicator lit up red suggesting they weren't on, but I'm guessing the mobo has an onboard speaker that should have sounded anyway?  Despite what I said about the DC doc in my last post I don't see how I can go forward without installing a new one.  I just ordered in on ebay via your link.  Is it possible my problems are simply due to a bad or inadequate power problem or maybe I'm just not getting a good power connection despite the blue light? Does this new issue change anything about your diagnosis that it's the mother board?


Looking under the RAM as you suggested, the part number it shows is 496871-001 and written underneath that is 7F0944.  Is this interchangeable with the number you listed?  When looking on ebay, is it fair to say that 1000, 1100, and 1200 would all work for me?  I'm not familiar with the dv8s.  I'd consider a peformance hit if it saved me money, but I don't want to pay more to increase speed.  $460 is too much.  Are there off-brands to consider or am I pretty much limited to used mother boards?


So I would save my ram, CPU, and graphics card and use them with the "new" mother board, right?   Sound is probably onboard?    Will I be able to snap these into place (like with desktops) or is this going to require soldering or special tools?  I'm not looking for detailed instructions but I'm just wondering what to expect.  Again, I'm familiar with building desktop components.


I knew using the power button to turn off was bad and have explained it to my wife on many an occasion, but well... you must not be married. ha ha.  Even so, I don't think the hard drive is my issue because I never get that far in the bios or boot.  Good to know though.


Left side made more sense when I tried the smaller USB drive.  It had a light to indicate it was powered.  I don't think the "right" side of the laptop even gets powered until later on in the boot.


Boot time isn't the problem.  It's after the login and the desktop appears that I don't dare start any apps too soon because there's a good chance they'll hang.  I think I got most of the bloat ware removed.  I tried to get a clean install DVD for Vista from a friend or online and then use the vista key that came with the laptop but by the time I started looking it was too late.  I use true image and restore back to a cleaner image from time to time. 


When you say the board has had the biscuit I guess you mean it's no good.  Where are you from that that expression is used?


The more I look into it, the more I agree that it's worth trying to fix the HDX.  Besides the issues I mentioned, the other thing that always bugged me about this laptop was the volume level.  Often when watching certain movies I just couldn't crank the volume up enough to hear it well.  I couldn't find a solution with software, although VLC player was nice in that it has a build in volume doubler.   I tried a usb speaker which made it louder but quality went down and I didn't like to have to have an extra part.  Is there a way to upgrade the speakers on this laptop? 


You've been so helpful I feel guilty pressing your for more info, but going back to mother boards, I'm not sure I understand my options.  Being I didn't build it, this was the one PC I didn't have to study about the latest processors and buses and everything.  If I'm willing to sacrifice a little performance do I have some other options or do I pretty much need to stick to the model number?  I guess a lot of these ebay sellers are regular retailers.  Is there any dealer you like and find particularly reputable?  I see some of them offer returns.  Is it worth getting a board with a 30 day return policy to give myself time to trouble shoot?  Given your experience, helpfullness, and knowledge, I really want to take advantage of any advice you have to offer.

Regents Professor
Posts: 4,523
Member Since: ‎12-28-2009
Message 10 of 46 (4,474 Views)

Re: HP HDX18t light up but wont boot. Blinks once

[ Edited ]

I would replace the power jack first as that may be the problem, at any rate that needs to be dealt with first to eliminate that issue.


 That link to that mother board will not work unless you go out and buy some DDR3 RAM, yours DDR2.


 When ordering a board I would stick to your part number (496871-001) This board has 512 MB of video RAM. Upon checking with all the model numbers, if you wanted to go to 1GB of Video memory you would have to go to DDR3 RAM. The DDR2 RAM in yours is not interchangeable with DDR3.

 To answer your question, only the 1000 series would work, unless you went to DDR3 RAM.


 You would reuse your CPU, fan and RAM, the video card is soldered to the board and the replacement will come with it.


 Lets get the thing up and running first before dealing with the sound, but if you go into sound properties there will be a box to tick "Disable all enhancements" (that will improve the volume) and NVIDIA also has its own sound driver and if that is enabled, the sound should improve greatly. Some models also came with IDT High Definition sound which has to be enabled. All this can be found in the control panel.


 The speakers are separate from the MoBo, you will find out ounce you get in there, but not upgradable. The only thing in most laptops that is upgradeable is the processor. There are ultra expensive gaming machines where you can upgrade the video card, but they are few and far between.


 "Had the biscuit", I don't know where I got that from. I have a couple of British cars and there is a mechanic I occasionally by parts from. I have known him for many years and he uses that term. So I guess I got it from him.  Smiley Happy


 Don't feel guilty, there is a thread here that is four pages long of me helping this guy install a fresh copy of W7 on his machine. Smiley Surprised


 Here is a guide that I edited early in the thread :


 GT9600 with 512MB of video RAM and running DDR2 memory 496871-001  (This is the only one that will work for you)

GT9600 with 512MB of video RAM and running DDR3 memory 506494-001  

GT9600 with 1GB of video RAM and running DDR3 memory 506495-001

GT130 with 1GB of video RAM and running DDR3 memory 519592-001

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