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HP Pavilion dv7 power adapter cable
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Posts: 5
Member Since: ‎07-15-2010
Message 11 of 69 (10,921 Views)

Re: HP Pavilion dv7 power adapter cable



son's pavillon developed the trouble.


we installed a new cable, which is very un-fun because it requires complete disassembly (motherboard out).


The symptom did not change even a teensy bit.   machine refuses to accept power from the jack which means once battery runs down you have just a thousand dollar paperweight.


we charged the battery partially from an external source by folding aluminumn foil to go into those teeny slots, then hooking to a car battery charger.  got it up to 14.6 volts.   computer runs fine from battery.


disassembled again and continuity checked from power jack center pin and barrel to tracks on motherboard behind motherboarrd connector. satisfactory readings (zero ohms) so we believe we have a good job on jack&cable replacement..


I believe there is a flaw in HP's "wake up circuit" that causing this problem.  You'd think they would offer information to hobbyists about how to fix it at our own risk.


plan now is to find which two pins in battery bay carry power.  tthere's about six of them and they are not bussed together. we will apply nominal 14 volts (midrange of battery) to those two pins ,  use as a desktop.


If anybody has succeeded in either fixing the motherboard's wakeup circuit  or  going in through battery terminals please post how you did it.


I have been a fan and customer of Hewlett Packard since 1964.  Back then they were a first class company. 

That they'd produce such an abomination as this, worse let it go on for years, is appalling.


HP's two founders must be really ashamed of current management..


analog ,  the old tube guy

Posts: 1
Member Since: ‎08-24-2010
Message 12 of 69 (10,902 Views)

Re: HP Pavilion dv7 power adapter cable

Wow, kind of glad it isn't just me. Like all of you my cord was loose from the start on my HP laptop. And just like you, a month out of warranty it just stopped working completely except the little light on the side of the computer where the plug goes. I have been searching for an answer and took it to Best Buy to see if they could tell me if it was just the cord. Of course it isn't. The cord may be gone as well, but he said it was an internal connector causing the problem and they could send it out but I had to pay eighty dollars up front since it was out of warranty and then it might only cost one fifty to get it fixed but no promises. I didn't pay it and don't think I will. I have been a die hard HP computer buyer for many years. In fact, my first computer in the 1980's was from this company. I love my desktop, but I am now convinced that it is a rip off company and will never again make the mistake of purchasing another HP. I was very disappointed in the customer service when I tried to call them including the fact that they took me through a half hour question poll before telling me that  I would have to pay $100 to have them even talk to me. I just had a question, I didn't even want them to fix it. If they would have asked me if it was under warranty first, I would have told them that. But no, they wasted my time instead. I need my laptop for my work, but I guess I will have to wait until I can buy a new computer because it was not okay that it died on me while I was working. That is just not cool. I now despise HP and would never suggest for anyone to purchase the computer after this trip down horror lane.

Posts: 5
Member Since: ‎07-15-2010
Message 13 of 69 (10,890 Views)

Re: HP Pavilion dv7 power adapter cable


wow is my face ever red.`


the trouble with harsh words is yuo so often wind up eating them.


We got son's laptop going, after three days of experimenting.


we had two chargers,  one only a few weeks old , that gave exact same symptoms = computer ignores charger. yet both chargers showed 19 volts between center pin and outer shell of round connector that plugs into computer.

So we believed they were both okay.

Which meant trouble was internal to computer.


Well, we were wrong,  both chargers had defective cables - the one that goes from charger to computer.  It's hardwired into charger and has round plug at computer end.

That cable is fragile.  One was broken internally 1/4 inch from charger,  other was broken internally at plug.


Troubleshooting is hard because it's not obvious how the thing works.

I hacksawed the chargers open to see what we had.  It's a pretty simple looking switching supply.

The wire that goes up to computer is a three conductor cable not two, and the center pin is not power.  And it's not described in the manuals,  even in the connector pin assignment section.


Here's what you have:

Looking into the computer jack with a magnifying glass and light ( i used morniing sun)  you'll see it's a center pin surrounded by a barrel.  Barrel has an inside and an outside.

You will see---

1.  center pin,  it's gold and buried down in the plastic. It's too small to carry 4 amps and that's what i thought was the trouble.  It is connected to white wire at motherboard connector.


2. Inside barrel has 4 brass fingers.  Orient so the LED is at 12 o'clock and you'll see fingers at 12, 3, 6 and 9 o'clock.

These fingers carry the + 19 volt power to computer.  Well, the ones at 6 and 9 o'clock do,  noon and 3 are not connected. +19 power arrives at motherboard connector on red wire.


3. Outside barrel has six brass fingers, at 2, 3, 4, 8, 9 and 10 o'clock. 2, 3, and 4 are not used,

2, 8, 9 and 10 are the power return (common, or ground) to computer.  It arrives at motherboard on black wire.


4.  LED  is connected to yellow wire and controlled by computer.  Other side of LED is jumpered to black wire,  common,  outside barrel 8,9,10 o'clock.


That's what is in computer.


On power supply you have:::

 a double shielded cable that goes to round power plug for computer.


Center wire is blue and very small - i don't know what it does.  Thought it was remote sense but ddoesn't seem to affect power supply voltage.  Some mysteroius communication between power supply and computer.  It reads 19 volts to common with a ten megohm voltmeter but only 5 volts with a 2kohm/volt meter so it's capable of only a few midroamps.


Outer shield is the power supply return wire and it goes to printed circuit in extreme lower right corner of power supply circuir board.  One of our supplies was marked "com".  one was unmarked.


Middle shield is + power to computer.  It goes to opwer supply PC board  just above return wire in a hole marked "vout" on one of our supplies and "+19V" on the other. 


That's it.  Again i dont know what the center wire does but it doesn't act like remote sense.


If anybody else can fill in more pir=eces of the puzzle please do.


I found middle shield broken at connector end on one supply and at computer end on other supply. Repaired both witjh solder and heatshrink,  taped supply back together and glues it to a plank.  Ugly but better rthan new supplies at a hundred bucks each.


Plugged 'em in and computer runs fine from either one.


Moral of story is - to check yuor charger read from outer barrel to inner barrel,  not center pin.  And use a cheap analog voltmeter not a DVM, you need to load the supply to a few tens of microamps lest it fool you.


HP - the stuff is well made but your tech manuals are not up to the standards for completeness and clarity that you set in 1960's.  Cant you see from this board how much pain those fragile cables are causing the world?


analog,  the old tube guy.  ( humbled again.)



Honor Student
Posts: 1
Member Since: ‎09-13-2010
Message 14 of 69 (10,606 Views)

Re: HP Pavilion dv7 power adapter cable

My laptop is now in need of its 3rd power cord.  It's absurd to spend $80 every six months on power cords, yet the computer is in perfect shape and works well.  What to do? 

HP clearly knows this problem exists, and are playing dumb.  After all, they're getting $80 infusions from all of us every few months...

I think some sort of class action activity would be in order, too.


Posts: 1
Member Since: ‎09-23-2010
Message 15 of 69 (10,455 Views)

Re: HP Pavilion dv7 power adapter cable

Yeah my Dv7 is doing the same thing i got it this past august 2010 and it is now doing the same thing. I was playing a game and then all of the sudden it went dim like it was unplugged from the wall. I look at both ends and they were both still plugged in the computer and the wall. I contacted hp and i am now shipping it back to them so they can check it out. I have a feeling that it going to keep doing this, considering all the other posts about this is happening. Im sure they will just give me another power cord and then it will just happen again. which if it does i will return the piece of junk, its only a month old.

Posts: 1
Member Since: ‎09-28-2010
Message 16 of 69 (10,355 Views)

Re: HP Pavilion dv7 power adapter cable

I have a HP Pavilion dv9000.  It has the same problem with the pin.  I REALLY liked this computer until I started having problems with the power connector.  I will not be buying another laptop from them, no matter how much I like it.  I cannot afford to lose business information because I use it for my practice, and I am also working on my dissertation.  If the plug jiggles at all, then it quits charging and my information along with it.


I bought a docking station thinking I could plug the connector into it, but it doesn't fit.  It's just a very disappointing and frustrating experience.

Posts: 1
Member Since: ‎09-28-2010
Message 17 of 69 (10,349 Views)

Re: HP Power charger

Having the same thing with mine loose day one, have to rotate it to get lucky to get it to charge and when your not paying attention, it just runs down plugged in-- Class action suit sound like the only way to resolve

Posts: 21
Member Since: ‎09-28-2010
Message 18 of 69 (10,318 Views)

Re: HP Pavilion dv7 power adapter cable --- Analog

[ Edited ]


The post that starts with "wow is my face ever red." (post 14) is an excellent post. Clarifies the situation.

Thanks for the detail.

Posts: 1
Member Since: ‎10-19-2010
Message 19 of 69 (10,050 Views)

Re: HP Pavilion dv7 power adapter cable

I have had my Dv7 now for 10 months with no issues, until now.  2 nights ago we plugged in the PC and the LED came on showing it was charging. We unplugged it to use then plugged it back in as we have done lots of times, but this time no LED.  I right away checked the cable, even moved to different plugs in my house.  Still nothing!  So I put it into my HP backpack and went down to my local PC repair shop.


When I got to the repair shop and took out the laptop his eyes got this look of disgusts and he said let me guess a power problem! To which I replied yes how did you guess?  He had 2 come in just that day he showed me with power issues related to the actual port inside the PC.  He appeased me by grabbing a new power adaptor showing me that it also did not work making it related directly to the internal port.  He said they are coming loose and are very poorly made.  His customers have seem some success in getting it covered by HP but most send in their PC only to get the finger pointed at them.


So I called HP since the machine is under 12 months and got a woman that seemed to be very pro HP and how could they possibly make something wrong or bad! I told her what I have stated above and she replied with "The TECH is not an HP TECH so has no idea what he is talking about" I then said it was simple process of elimination and he told me to go to HP so why lie about the other Laptops, he was not selling me anything.  I then told her that I went on Google and found numerous posts such as this one. She said “anyone can write anything, plus it is not your system and how can they have the same issue!”  I informed her that I was on HP support forms and that the model talked about was the same... Then nothing... Se proceeded to try and up sell on faster shipping or I may not see the PC back for 6 weeks or more. I refused, she then stated that “if it is found to be a consumer issue the charge will be $389.”  I asked what that is based on and how she arrived at such a specific amount. She paused and then said “that's what it is for that part of the PC.”  So I’m thinking this is going to end in it being my fault regardless!


I will be sending in the PC once I get the package from them and will update this post.  I'm just very disappointed so far and I own other HP products.  I may reconsider my choices before I buy an HP again.  Also with all that I have found I would like to think there will be some kind of Class Action or recall on this part because a $1200 laptop is something that should be good for more than 12 months.  I know I can't afford 1 a year! Get it together HP…

Posts: 296
Member Since: ‎12-12-2008
Message 20 of 69 (5,559 Views)

Re: HP Pavilion dv7 power adapter cable

To any of you considering getting a different brand of PC:  I've read several posts saying that the average quality of Dell PCs is even worse.

† The opinions expressed above are the personal opinions of the authors, not of HP. By using this site, you accept the Terms of Use and Rules of Participation