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How to repair HP dv6 notebook power adapter

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After years of lurking it's time for me to give something to the instructables community. I hope this can help!

By the way,

I WILL NOT TAKE ANY RESPONSABILITY for accidents or injuries occured trying or as a result of this instructables! DO IT AT YOUR OWN RISK!


and, if you want to give a try,

BE CAREFUL! Use glasses, gloves, mask and everything you need for YOUR SAFETY!
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The power adapter of my HP dv6 notebook died a month ago.
Using a multitester I noticed that there was zero volt output. also putting my ear near the box I could ear a strange noise, some kind of syncopated twittering!
So I went to my computer shop and bought a new adapter, a universal one, but I wasn't completely satisfied with this solution:
- the new one has shorter cable, annoying!
- it doesn't connect very well, sometime I have to move the jack in and out until the notebook see it again;
- the new adapter has only 2 pins output while the HP one has 3 pins.. that third pin must be useful someway!

Enough! I've decided to open the black box to see If I can fix it!
 
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Step 1: Tools

Picture of Tools
What I've used (and what maybe you need):

- Scissors
- Japanese sharp blade (x-acto knife should work well too)
- pliers
- tweezers
- tin wire
- insulating tape
- duct tape
- multitester
- soldering iron
- desoldering pump
- dremel with cutting tip

Step 2: Opening the adapter

The adapter did'nt work anymore. strange noise. using the multitester I noticed that the ground and Volt pin where short-circuited!
I supposed the problem should be in the cable. Time to open the black box!

Memo: Before going any further, unplug everything!

The box is made of two plastic shells fused together, there are no screws or clips, the only way to open it is cutting the junction line. Using dremel with cutting tip it take just 5 minutes. Luckly the inner circuit is protected by a metallic shell, so don't be too worried to cut something inside, just take your time and be very careful near the input and output cable.
When you can see metal on all the sides, gently open the plastic shell. there is some glue to keep all together, but it will surrender soon.

Step 3: Unsoldering the cable

Before desoldering take note of how cable are connected to the pcb.
In my adapter there are 3 pins: GND (ground), ID (identification?) and VOUT (voltage output).

My output cable is coaxial and it is connected this way:
outer layer go to GND,
mid layer go to VOUT,
inner layer to ID.

TRIVIAL NOTE: Seems like the ID pin is used for some kind of communication between adapter and notebook.. It transmit a signal at lower tension so that notebook recognize the adapter as an original HP product!

Unsolder the cable one pin at a time, from outer to inner, using the unsoldering pump and helping yourself with tweezers.
If the industrial soldering doesn't want to melt use this trick: melt some of your toxic and full-of-lead soldering wire on it and heat with your soldering iron. This will mix the two kind of  tin lowering the melting temperature.

Control with the multitester if the VOUT and GND pins are still short-circuited. I hope the answer is no :)

OPTIONAL PART:
Maybe now you want to check if the adapter works well before proceding..
This method is dangerous so please skip this part if you don't feel like doing it and be very careful!
Put the metal box back in one of the plastic shell's halves in a way that it is insulated from your desk and everything else. Choose the best side to face you considering that you want to easily reach the pins with the INSULATED tips of your multitester. Without touching any part of the open adapter plug the input cable. All you have to do is touch VOUT and GND pin with multitester tips to check if there is a correct potential difference (of 19 Volt for mine adapter). Checked? Unplug!

Step 4: Reparing the cable

So you know there is a short-circuit somewhere in the cable.. but where?
The best way to proceed is to cut away the last part near the black box, right after that kind of black plastic spring that should help to preserve the cable from broking (..and always fail!).
If the problem is in the cable, you can be sure it's somewhere in that critical zone. Check with multitester if now is ok, or cut another few centimeters and test again.
Don't throw away the plastic spring! Try to remove the broken cable from inside the spring and to put back it around the remaining good cable. I've had to cut the spring in three part cause it was soldered to the cable, yet it has been still useful.
Once the spring is back around the cable, strip the wire one layer at time. Looking at pictures you can see that I cut the wire on the long way cause I reuse the plastic coating for insulation and strenght.
Twist together the wires of each layer and insulate with tape. Check to which pin each wire must go. Try to rearrange the three wires so that it'll be easy to solder back it on the adapter, then block everythig with tape.
Resolder the wires to the adapter, from inner to outer pin.

Step 5: Closing the box

Picture of closing the box
taped2.jpg
taped.jpg
tape.jpg
Put back together the plastic shell and block it with duct tape. Be careful to not leave exposed any metal part.
You're done! Plug everything.. and cross your fingers.
Carburn made it!1 month ago

As for me, problem with power adapter was in plug. The soldering was disengaged on VOUT wire. After soldering notebook has become charged again))

DSC05815.JPGplug.jpgDSC05816.JPGDSC05817.JPG
vtpa made it!2 months ago

Hey, it save me a lot of money!
This procedure works with other chargers HP... My model is Pavilion dv4 (out 18,5 V).
As can be seen in the pic, the position of the points in the circuit board is little different, but with a multitester and seen in the back, this problem can be solved easily!

Thanks a lot for this tutorial!

CAM00704.jpg
turtlewax2 years ago
Duct tape is not good around molded plastics as the glue tends to melt the plastic over time. Overall good instructible for novices. It is very common to see 'mechanical' failures in laptop power supplies since the cord gets folded up to put it away for travel. Another common problem is capacitors that are rated for too low a working voltage and the capacitor ends up getting too hot and bulges due to electrolyte leak and fails.
Note: Using a vice is best bet to crack open the battery charger case as using a knife runs the risk of cutting an internal part such as the transformer or a capacitor.
Keep up the good work!
Its pretty dangerous. Did it work for you afterward? I expect it did. My hp power didn't work before and i didn't repire it.I bough a new one from eachbatt.com.It is a great source for OEM chargers if you can find them.
tsaluste1 year ago
Thank you for the instructable. This saved me around 50 bucks for not buying a new one of these chargers. I liked how this instructable is damn accurate. I also had the exact same problem when de-soldering the pins and adding a bit of new solder fixed the problem there! I reclosed the adapter with superglue as I already had this in hand. Will report if superglue fails.

Cheers!
PS. To open the case, I used paper knife. I had to cut manymany times and had to pull hard on the handle.. but in the end the cut was smooth and had very small cap. No plastic was lost so reconnecting the adapter was a breeze.
reloadx1 year ago
Instead of cutting all the way around the plastic adapter box with the dremel, you can cut just a slit so that you can insert a flat head screwdriver into it and then when you twist the screwdriver, the plastic box pops open. It's a little faster, it looks cleaner, because you only cut a little slit and since it kind of snaps it back into place, it makes it easier to glue.
omnibot2 years ago
Nice job. Looks like the same one I had.
I never glued mine shut either since it seemed to me that it was the twisted shielding/groundwire that caused the break in the first place. Also that third pin gave me grief, it seems HP no longer makes adapters like that. I wonder why XP
I broke open the connector of my old one, when I built the adapter for a ebay-bought 120W supply.. it had the generic barrel plug at the end of the supply cable, and a stack of 'finger' adapters, going from the socket for the plug, to whatever end your laptop needed.. Except... NONE fit the huge inverted barrel (tube with a tiny pin in center) HP started using for the DV6 series. I ended-up making a simple adapter for the 120W supply, by clamping & soldering the outer shield of the old HP supply to a Radioshack coaxial socket plug (RS # 274-1577), running the center connector of the plug to the inner shield (yep, tri-axial) of the HP plug, and leaving the center pin floating. I've been running my DV6-3210 on it since with no problems. (I only had to ream-out the end of the RS plug, so the HP plug would fit through.) (http://s197.photobucket.com/albums/aa306/gelfling6/Arduino%20Stuff/?action=view&current=Snapshot_20120201.jpg http://s197.photobucket.com/albums/aa306/gelfling6/Arduino%20Stuff/?action=view&current=Snapshot_20120201.jpg and http://i197.photobucket.com/albums/aa306/gelfling6/Arduino%20Stuff/Snapshot_20120201_1.jpg ... excuse the ugly mug behind them.)
1337engine2 years ago
Right! just need to buy a good dremel with cutting tip...
killbox2 years ago
I usually use a wood working chisel. ive also used an exacto knife screwed into a soldering iron as a "hot knife"
Love the hot knife idea! I'm going to try that on something!
here you go, its a little slap and dash. need to take photos of the one I made/use at home. Rather than the new one I just made for Quelab (our local Hackerspace)

http://www.instructables.com/id/A-Hot-Knife-cuts-plastic-rope-opens-welded-pla/
you can also get a junkable kitchen knife (one with a good riveted on handle.) wrap the handle in kapton tape and just heat the blade over a stovetop burner/torch

but like all things involving melting plastic. do it with plenty of ventilation

Obviously you never use the knife for food again, as it may have burned on plastic.
The "hot knife" would make a great idea for an instructable! I want to see that! XD
I will work on one. Its pretty dangerous. imagine a exacto knife that is now cauterizingly hot. what i need to do is find a good source of hobby wood burning iron handles, they tend to have the heater more inside the handle.
lpciprian2 years ago
I have the same multimeter and desoldering pump :D
RJSC2 years ago
Not trying to put you down, but, it you open it like this:
(not my video)

And then put some cyanoacrylate glue (the real name of superglue) along the inner part of the seam and put a weight or a C clamp to hold it closed while drying, you get it to look as good as new!
Even if you need to open it later, the glued power supply will crack open again with the same method.

I've done it on 2 different DV6000 chargers I repaired already with a short circuited cable on the strain relief.
It seems the strain relief is not very good, or people pull the cable to much.
hastypete RJSC2 years ago
Interesting variation on just using a hammer.
I'm looking at this instructable and wondering why go to the effort of using a saw. I've opened and repaired the cords on about 6 adapters using just a hammer to open the case. All you do is give some sharp hits to the corners with the supply on a solid surface. the glue all breaks and it comes apart.

I like the idea of the knife though and will definitely try this next time.
nwlaurie2 years ago
At Step 3 you say 'Before desoldering take note of how cable are connected to the pcb'.
Nowadays with a camera on (almost) every phone, it is really easy to snap a photo of the wires/connectors/layout before you start taking something apart.
I (almost!) always do this before dissembling a piece of unfamiliar kit.
I take pictures of stuff as I do it in case it can be made into an instructable, but I still rely on drawing things by hand to make note of connections and so forth. Maybe it's just how my brain works, but I think it's clearer.
ac-dc2 years ago
A few random comments.

- If you suspect the cable, get some needle (piercing) probes for the multimeter and you can check continuity, although when you measured a short that isn't the likely problem - the short is more likely a burst capacitor - but I have not read far enough in the instructable to know, this is just a guess.

- Instead of opening the case with a dremel tool, try putting it in a vice and applying pressure to bulge and pop the seams. Sometimes this will work, other times not, but if it works then your seams still have a lip for a better reassembly and sturdier glued together joint. Otherwise I hold them together with nylon wire ties.

- On your wire the third "ID" pin is probably Current Detect, the I being the electronic symbol for current. It does not transmit a signal to recognize the adapter as an original HP product or anything like that, it allows the notebook to detect when current lowers and the charging cycle is near completion. Some notebooks have this built in instead.


- Lastly, most of the time a failed adapter has a failed capacitor or transistor in it. Some of the time the cable is broken, but it is rare to have the problem seen here with a shorted cable. Good job tracking down the problem but I wanted people to be aware that it usually takes more work than this to fix one. Also, ebay is a good source for replacement OEM power adapters cheap, people end up parting out dead notebooks and have the power adapter left over to sell.
Kasm279 ac-dc2 years ago
Ebay is a great source for OEM bricks if you can find them, I ended up getting one for my old thinkpad for less than $5
After several years of hard use on my dell adapter, the plug broke. I found another one, and spliced the new plug on. Then the Watt rating dipped when it heated up a few months later. I couldn't fix it, once it got to a certain temp, it stopped working, but I could do the next best thing...PUT IT IN THE FREEZER! This way it took longer to get to the fail temp. There's also some bits about bringing the metal atoms in the adapter closer together, raising efficiency too... If anyone is considering this, put it in a zipblock bag first, to reduce water condensation. KEEP IT DRY!

I'll take the opportunity to diddo the "I WILL NOT TAKE ANY RESPONSABILITY for accidents or injuries..." disclaimer at the top of this tutorial. Throwing electrical devices in the freezer...probably not the best idea, but I got reports done.
mickeypop2 years ago
For a professional seal on the case.

tape some stiff paper(business card works great) around the inside of the case allowing about 1/4 inch above the edge before closing the 2 halves together.

this make a dam to keep the sealant out of the electronics.

seal around the gap with epoxy then dress up the gap when the epoxy starts to get tacky.

When done you won't see that the unit was ever opened. Just looks great this way.
wa7jos2 years ago
When putting the box back together, I use silicone sealant, RTV, or Shoe Goo to glue the two halves back together. Use some tape temporarily while the glue dries. It looks better than duct tape, and it's easy to remove should you have to get hack into the power supply again. Also, duct tape will act as a thermal insulator. The case of the power supply needs to be able to dissipate the internal heat.
ac-dc wa7jos2 years ago
It's a plastic case, duct tape will not make a significant difference in thermal dissipation.

Problem is, when duct tape is heated the adhesive becomes gooey and can leech out making a mess and being vinyl, heat and UV (sunlight) can make it brittle and crack.

Certainly adhesive is a good choice, but consider using adhesive that actually melts (dissolves) the plastic so it rejoins. For example PVC cement instead of silicone or RTV etc. It is also better than superglue. Test what you plan to use on an inner area of the case, let it sit for half a minute on the plastic then scratch the area with a toothpick. If the plastic has softened from the adhesive you know it is dissolving it and will be a good adhesive to use.

PS - if you really think your adapter is getting too hot, drill a few tiny vent holes in it, but be sure they aren't big enough or a a child isn't going to be near it so there isn't a risk of something being stuck in the holes - same situation as with a wall AC outlet, you have to assess risk then decide what to do.
neilh2 years ago
Nice.

IIRC the ID pin is used to tell the charger circuit if is safe (meaning you bought a brand name power supply) to charge the battery, as well as to communicate the power rating in Watts of the power supply.

A lower power rating on the supply indication is needed if the machine can not run a full power for the given supply and has to run at reduced speed. (take a machine shipped with a 90W/115W supply and plug a compatible brand name 65W supply into it).

The ID seems to usually be one of the 1-wire EEPROM ICs from Maxim/Dallas Semi or similar vendors.

I once had a HP car charger that I modified to power a Dell laptop, but not charge the battery since it didn't have an ID pin connected to an eeprom with the right data in it.
MollyBednum2 years ago
You guys dazzle! This is one of those egregious "for the gods' sake PLEASE HACK ME" products.

I've had nothing but laptops since the '90's. Several different brands, and ALL the power adaptors were (1) designed to break early and often, (2) expensive to replace, with a markup comparable to movie-theater popcorn, (3) unique - or so they said - to each and every model, (4) only available through the mail, forcing "road warrior" users on deadlines to carry a heavy, clunky, bulky backup everywhere just-in-case.

My (at least theoretical) approach was to shore up those P.O.S. strain-reliefs, with duct tape if that was all I had, as soon as I got the darn thing out of the box. I never had time to make it look pretty - when I remembered to do it, which sometimes I didn't.

Good to see various folks working on contingency plans!
csiquet2 years ago
I already fixed 2 chargers the same way but I usually remember to do an instructable when I'm done...
Phil B2 years ago
Did it work for you afterward? I expect it did. The area around the strain relief is always most prone to breakdown and frayed wires internally. I recently did a similar Instructable, but the problem there was that the frayed wires in the strain relief were causing a short that brought an immediate and spontaneous shutdown to her computer.
eriol (author)  Phil B2 years ago
Yes it worked! I have to add an happy ending to the instructable ^ ^
wrksnfx eriol2 years ago
What you can do after fixing the power supply is you tape the the power cord end that goes into the computer partly onto its side of the power supply so loops around in the direction of the AC cord goes into it as to prevent this from happening again. I did this on my power supply on my HP pavilion zt3280us laptop and works fine except I just striped back wires where they broke and soldered them back together and taped all around the spring part as you called it and the entire power supply block with electrical tape.
Gelfling62 years ago
Sometimes, you needn't use a dremel to cut, or risk striking wires when cracking open a power supply.. Of You're careful, place the case between the jaws of a fairly good sized bench vice, and squeeze it on the corner ends on the sides (across the seal)..
v v
First, this side, { [====] }-then this side..
^ ^
the seal should break, unless they went to extravagant measures to seal it.. This way, a few drops of crazy glue, and you can re-seal it..

I repaired an old Dell supply like this, and was able to re-seal it with little noticeable damage.

A lot of wall-wart transformers crack open the same way.
Instead of cracking the power supply you can use a hacksaw with its blade or wrap a cloth tightly around the blade to make a makeshift handle if you don't have a hacksaw handle and saw along the seem to prevent damaging the supply further just be CAREFUL not to cut yourself .
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