My old but good Dell Latitude E6410 notebook stopped charging and working with the original Dell AC power adapter some months ago. It was working only sporadic but in most of the cases the blue led of the AC power adapter went off after plugging it in. I tried an other Dell power adapter but with the same results so I thought it was a hardware fault on the notebook side.

Nevertheless Krischan had an idea and tried an 20V power adapter from an other manufacturer. Turns out this one worked powering the notebook but charging was still disabled. An error message popped up in the BIOS “AC Power adapter could not be determined“.

We did some research and found an interesting article mentioning an additional data pin (inner pin of plug) of the power adapter which is used by the notebook to “communicate” and validate the power adapter via 1-wire-protocol.

So the next idea was quite unusual but a step into the right direction. We used the power wires (PWR/GND) from the non-Dell power adapter and wired the data pin + GND of the plug to the original Dell power adapter.

We tricked the notebook into “thinking” it was still connected to the faulty 19V power adapter via the data wire and used the ac power from a secondary working power supply.

**WARNING**: Depending on the One-Wire-IC or the programmed value the notebook is detecting everytime the same value like “90W AC-power-adapter” independent which adapter is plugged. If you proceed with following hack and then take a weaker 65W-AC-power-adapter, it could or will overheat by overload!!! (maybe deactivating Express-Charge in BIOS could be a dirty workaround [untested!]) You should know what you do. Alternative and better way is to reprogram with tools like OneWireHub or DS2502_DELL_PS the One-Wire-chip from other AC-adapter you want to use for response to Dell notebooks. Background-info like in this comment: https://news.ycombinator.com/item?id=23304973 Another hack uses an ATtiny 13 to emulate a OneWire DS2501 IC

In the next step, we cracked the case of the Dell power adapter and desoldered the transistor style chip mentioned in the article above. It is connected to the data wire and marked with “DALLAS – 250X” (MAXIM chip) or “28W2M1I – BYE”.

The next idea was to put this chip directly into the notebook. We traced the data pin from the jack back to the connector on the motherboad. We cut the data line and soldered the “28W2M1I” one wire chip together with a resistor and diode to the board connector. The diode and the 120-130Ω resistor are probably optional and belong to the protection circuit.

Surprisingly this hack is really working! We can now use any power adapter and the notebook is running and charging well. The BIOS still receives the correct information from the 1-wire chip, which is now soldered into the notebook.

AC adapter is found and charging the battery!

Update 2020/05: This post got featured on Hackaday.com (archive), thank you for all this feedback :)