The “Dell AC power adapter type cannot be determined” problem description
I have brand new Inspiron 1520.
Battery fully charged, when I unplug the charger from the wall, but let the plug in the Inspiron for a while (let’s say a night), when I startup my computer, I get the message “The AC power adapter type cannot be determined. Your system will operate slower and the battery will not charge. Please connect a Dell 90W AC adapter or higher for best system operation” (needless to say that the power adapter IS a Dell 90W…). Unplugging and replugging the adapter solves the problem.
Battery fully charged, when I unplug the charger from the wall, but let the plug in the Inspiron for a while (let’s say a night), when I startup my computer, I get the message “The AC power adapter type cannot be determined. Your system will operate slower and the battery will not charge. Please connect a Dell 90W AC adapter or higher for best system operation” (needless to say that the power adapter IS a Dell 90W…). Unplugging and replugging the adapter solves the problem.
The problem happens frequently at Dell inspiron 1525,inspiron 6000, inspiron 600m, XPS m1330, latitude D600 and so on.
The “Dell AC power adapter type cannot be determined” problem cause :
There are many small silver wires creating a jacket around the cable that frequently fall out. After a few of them break from bending the cable during NORMAL usage there is a drop in voltage but still PLENTY to run and charge the computer.
Break open the power brick. (Yes, really break, beacause there are no screws)
And yes .. as many people suspected the small pin of the connector is the DATA line and is connected to a Dallas DS 2501 1-wire memory chip in the power brick. The 2501 is 512 bit EPROM with also an unique identification code. Measurement by oscilloscope made it clear that this chip is indeed DEAD, the ‘high’ voltage on the DATA line was about 0.6 V while it should be at least 2.2 V.
When disconnecting the data line from the memory chip and measuring the signal level on the DATA line when plugging in the connector in the laptop the signal level is back to a perfect 3.3 V and the laptop is clearly sending?request signals, so the laptop should be o.k.
Of course this minor defect can’t easily be repaired, because when buying a new DS-2501 as a replacement, first it should be programmed with the right data, so you need programming software/hardware and of course a power brick with a still intact DS-2501 to copy the data from!
Dell’s Customer service reply :
Hello All,
I am sorry for the frustration, but I am 100% confident there is no conspiracy afoot to sell ac adapters by designing them to fail. We warranty those parts and designing them to fail would drive up warranty costs. If your ac adapter needs to be replaced, I will be glad to dispatch you one myself [out-of-date information removed].
I am sorry for the frustration, but I am 100% confident there is no conspiracy afoot to sell ac adapters by designing them to fail. We warranty those parts and designing them to fail would drive up warranty costs. If your ac adapter needs to be replaced, I will be glad to dispatch you one myself [out-of-date information removed].
To all others on this thread, if you would like me to replace your ac adapter, please contact the site mods here to get my email address. Then email me your service tag, name and current ship to address. I will overnight you all replacement ac adapters and power cords. Thanks for your patience.
An expert’s advise about “Dell AC power adapter type cannot be determined”
Concerning this problem, I was also disapointed with the limitations imposed due to the PSID signal on my Dell Inspiron 1100 battery. So this is my solution.
OK the ID function is there for a reason, Dell designed it to help preserve the battery etc, but having emailed tech support with a request for a software override or some other solution to be able to switch off the PSID requirement, they either could or would not help. Just recommended I purchase (as people have said) more of their charging equipment etc. which I also think is a bit unreasonable.
They could easily update the Bios to allow user selection of this function.
Anyway, I ummmed and errred for a while, and then thought why not move the mysterious ID chip from the adapter to permanently inside the Laptop and disconnect the middle ID pin so the laptop ALWAYS thinks it has a correct adapter connected. Fine by me. And you can still adjust the power saving mode on screen anyway.
Now I don’t recommend this to most people as its quite tricky. I’m an electronics engineer and have experience with circuits etc. and it took me a couple of days to do it with inspiron 1300 battery. Remember warranties probably go out of the window.
The first problem is to get your good Dell adapter apart. The case is glued together, and withought butchering it completely, takes some effort to get apart with blunt knives etc. Then unsolder the end of the metal shield nearest the output cord to get to the back of the circuit board.
The (Dallas semiconducter) chip is near the output wires, and fortunately its a pretty simple circuit, just three components: The 6 pin chip of which only pins 1 and 2 are used, a protection diode across them, and a tiny 100 Ohm resister.
Very carefully (you only have one chip) unsolder those three bits (actually its better to replace the resister with a standard 1/4W), making note of the connections. Solder fine wires to the chip pins (I used one strand of a cable). Then add the other two bits to the wires laptop battery. Wrap in a little PVC tape with just the two connections showing.
The Laptop unfortunately needs a lot of dismantling to get to the back of the power socket. I had to take of the inspiron 6400 battery, the keyboard, the screen, unclip the wires etc. take out the hard drive, unscrew all the screws in the back, and lift off the top cover. Needs care.
Cut the middle connection from the back of the power socket so you get a little stub left down to the motherboard. Then just solder the appropriate pins of your chip package to ground and the stub, so that it sits in a good position clear of any screws etc.
The simple solution about “Dell AC power adapter type cannot be determined”
There are many small silver wires creating a jacket around the cable. After a few of them break from bending the cable during NORMAL usage there is a drop in voltage but still PLENTY to run and charge the computer. The whole thing about the CPU running at a slower speed is totally unnecessary and only there to further encourage a new purchase.
The wiring and AC adapter are DESIGNED to fail. I have never had one last longer than about a year. Oh, and if you try to get a non-Dell adapter (universal) it won’t work either.My macbook 13 battery has not the same situation.
This is basically an engineered weakness causing many AC adapter orders and a borderline scam if you ask me.
There are many small silver wires creating a jacket around the cable. After a few of them break from bending the cable during NORMAL usage there is a drop in voltage but still PLENTY to run and charge the computer.
Start laptop as normally with AC supply, after complete booting of system, turn off AC plug, just press the cable (coming from adapter) towards the adapter (with normal force) and Turn On AC. Surprisingly its charging my laptop battery.
Put it all back together, and it works well. I now get no more notifications of unrecognised adapters and full speed operation whenever I want. 
Some Dell customer say :
The excuse Dell gives for disabling the computer in this way, that the computer has to “adjust the performance to match the power available”, is a joke. How does the computer know how much power is available if it can’t identify the adapter? Why does running my computer at half speed somehow ensure that I will have enough power available, regardless of what adapter I might be using? If Dell really did have the customers’ interests in mind when creating this “functionality”, they would have provided a way to override it in the BIOS for those who know they have a powerful enough adapter. Clearly, this is simply a way to force people to replace lost or worn adapters (which typically are not under warranty) only from Dell.
Dell is notorious for these types of games. While researching this problem, I came across one case in which their desktop computers came with power supplies that looked identical to industry-standard ATX power supplies. However, if you attempted to use the power supply with a replacement motherboard that was not from Dell, it would destroy your computer. (see the wikipedia article on the ATX standard, where there is a section devoted to Dell: http://en.wikipedia.org/wiki/Atx .)
I was shocked to read one post in this forum in which someone describes having the same problem on their brand new XPS1530. I had this issue on my inspiron 8600 battery about four years ago. It’s one thing for Dell to try to lock people into using only Dell adapters, but continuing to do it after so many years of knowing all the unintended grief it causes for customers makes me never want to buy a Dell again. I just canceled my order for an XPS1530 after reading Matias’s post. (no joke. customer 95034710).
The Dell support solution about “Dell AC power adapter type cannot be determined”
1. Update the bios (I have A01, A03 is out). Ok, but I can’t. In order to do so, you must have the battery and the AC Adapter plugged in or the update program gives an error and forces you to cancel.
2. Motherboard needs to be replaced. Don’t think so, it worked just fine before on the older AC Adapter. Plus if they searched this forum they would see that that did not work for others with the same problem.
But obviously it is not helpful.
But obviously it is not helpful.
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