I am sorry if this post is too long, but what it covers took me a lot of time and effort to discover.   I will try and explain what I know of the Dell power adapters from my experiences.  I am no expert, but I think I have a good grasp on how they work.

I started learning about Dell power adapters about 18 months ago when the power jack on my wife’s laptop became loose, would only run at half speed and would not charge.  I ran across many sites with people having the same problem but not much in the way of answers other than buy a new adapter or new motherboard.  I did find one story on several sites about a guy that found the “identification chip” on the power supply, suggested that he had managed to read it and even proposed that it could be mounted directly to the motherboard so you would never get the laptop adapter message again.  I saw it as a challenge of my computer abilities to see if I could do this and if it would work.  It took much, much time and effort but I did succeed.

On older Dell power adapters the “chip” is a DS2501 OTP EPROM 512 bit Onewire device made by Dallas Semiconductor / Maxim.  I know this chip is in the PA-15 I have and in the PA-** that are rated at 60W and 90W, which I do not have handy to get the exact numbers.   I found finding real information on this chip hard to come by nor could I find any for purchase.  I could find more information on the DS2502 which is the big brother of the DS2501 with twice the memory, and these could be bought.  If the chips were bought they would have to be programmed.  This meant a programmer and the correct data to put on it.

I had to opt for cheap and there is no challenge in buying a prebuilt programmer except paying for it.   I found APP177 on the Maxim site for a serial Onewire programmer.  They have software for Java and Window available for download that supports the serial programmer.  The parts for the programmer can be sourced.  I built the serial programmer on a solderless breadboard.  I then discover that the software will not support a DS2501, it will not recognize nor read it.  It would read the DS2502 so the programmer worked; the problem was in the software.  I ended up having to modify their open Java software to read the DS2501 by making a container for it based off the DS2502 container then adding it to the program.  I finally got it to work.

I read the power adapter DS2501, programmed the DS2502 with the same information, and then soldered it to the laptop motherboard power jack.  I powered on the reassembled laptop, no adapter warning, the BIOS is reported a 90W adapter connected and the battery charged again.  I have since modified my E1705 and a few other Dells.  Recently I etched` a PCB and I now have my Onewire programmer permanently mounted so I can now program the DS2502s I have on hand when needed.  I would posts pictures but I have discovered that links to images are not displayed in this forum.

This is other relevant information.  My E1705 with a 256 MB GO7900GS came with a 90W power adapter.  When I would play WOW it would get so hot you could cook on it.  I then read on a forum that you could use a PA-15 150W adapter for the E1705.  I got one and it worked great until the center wire went bad, that was when I modified it.  I recently had the chance to work on a M15X with a PA5M10, which is also a 150W power supply.  This adapter came with a DS2502.  I tried the PA5M10 adapter in my sons E1705 (unmodified) and it accepted this much newer adapter without issue.

I think that the laptops only care that the power supply tells them they are from Dell and of certain wattage.   If the wattage of the power supply equals one the ones in the BIOS then it passes.  If it does not match or does not detect then the laptop runs half speed and no charging.  I also think that the DS2501 are out of production so will it only be on older power supplies.


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Dell Laptop Charger
I have some experience with these Dell power adapter problems and solutions. I had originally posted this on a Dell forum and I am too lazy to retype it so if some of this information is redundant I apologize. I also may have a an easier to program option to the DS250x series that does not require 12V but I have not got around to confirming it as I still have plenty of DS2502's on hand. Hopefully this is useful and if anyone has any questions I will do my best to answer them.


I am sorry if this post is too long, but what it covers took me a lot of time and effort to discover. I will try and explain what I know of the Dell power adapters from my experiences. I am no expert, but I think I have a good grasp on how they work.

I started learning about Dell power adapters about 18 months ago when the power jack on my wife’s laptop became loose, would only run at half speed and would not charge. I ran across many sites with people having the same problem but not much in the way of answers other than buy a new adapter or new motherboard. I did find one story on several sites about a guy that found the “identification chip” on the power supply, suggested that he had managed to read it and even proposed that it could be mounted directly to the motherboard so you would never get the laptop adapter message again. I saw it as a challenge of my computer abilities to see if I could do this and if it would work. It took much, much time and effort but I did succeed.

On older Dell power adapters the “chip” is a DS2501 OTP EPROM 512 bit Onewire device made by Dallas Semiconductor / Maxim. I know this chip is in the PA-15 I have and in the PA-** that are rated at 60W and 90W, which I do not have handy to get the exact numbers. I found finding real information on this chip hard to come by nor could I find any for purchase. I could find more information on the DS2502 which is the big brother of the DS2501 with twice the memory, and these could be bought. If the chips were bought they would have to be programmed. This meant a programmer and the correct data to put on it.

I had to opt for cheap and there is no challenge in buying a prebuilt programmer except paying for it. I found APP177 on the Maxim site for a serial Onewire programmer. They have software for Java and Window available for download that supports the serial programmer. The parts for the programmer can be sourced. I built the serial programmer on a solderless breadboard. I then discover that the software will not support a DS2501, it will not recognize nor read it. It would read the DS2502 so the programmer worked; the problem was in the software. I ended up having to modify their open Java software to read the DS2501 by making a container for it based off the DS2502 container then adding it to the program. I finally got it to work.

I read the power adapter DS2501, programmed the DS2502 with the same information, and then soldered it to the laptop motherboard power jack. I powered on the reassembled laptop, no adapter warning, the BIOS is reported a 90W adapter connected and the battery charged again. I have since modified my E1705 and a few other Dells. Recently I etched` a PCB and I now have my Onewire programmer permanently mounted so I can now program the DS2502s I have on hand when needed. I would posts pictures but I have discovered that links to images are not displayed in this forum.

This is other relevant information. My E1705 with a 256 MB GO7900GS came with a 90W power adapter. When I would play WOW it would get so hot you could cook on it. I then read on a forum that you could use a PA-15 150W adapter for the E1705. I got one and it worked great until the center wire went bad, that was when I modified it. I recently had the chance to work on a M15X with a PA5M10, which is also a 150W power supply. This adapter came with a DS2502. I tried the PA5M10 adapter in my sons E1705 (unmodified) and it accepted this much newer adapter without issue.

I think that the laptops only care that the power supply tells them they are from Dell and of certain wattage. If the wattage of the power supply equals one the ones in the BIOS then it passes. If it does not match or does not detect then the laptop runs half speed and no charging. I also think that the DS2501 are out of production so will it only be on older power supplies.

This is the link to my original post if it matters.