Embedded EEPROM Inside DELL Laptop for Charger Identification

My original DELL laptop charger was broken, I bought a cheap alternative charger from shopee.com as it is make no sense to invest much on an 8 years old laptop. Unfortunately the new charger doesn't fully compatible with DELL 14z (5423), it provides 19.5V to power up the laptop but doesn't charge the battery.

After searched in the web, found out that this is due to missing signal from the center pin. I've some spare DS2431 in the drawer, hence, I decided to follow Reference #2 approach to fool the laptop with a DS2431.

Disclaimer:

This article mainly as proof of concept rather than permanent solution. Using a non-official or incompatible charger may increase the risk of fire or explosion.

The author gives no warranty and accepts no responsibility or liability for the accuracy or the completeness of the information and materials contained in this instructable. Under no circumstances will the author be held responsible or liable in any way for any claims, damages, losses, expenses, costs or liabilities whatsoever (including, without limitation, any direct or indirect damages for loss of profits, business interruption or loss of information) resulting or arising directly or indirectly from your use of or inability to use this instructable or any websites linked to it, or from your reliance on the information and material on this instructable.

References:

1. https://hackaday.com/2014/03/03/hacking-dell-lapto...

2. https://nickschicht.wordpress.com/2009/07/15/dell-...

Hardware tools:

1. USB to UART dongle, TTL/CMOS voltage level
2. UART to 1-wire interface circuit, this circuit can be constructed out of a few discrete components. See https://www.maximintegrated.com/en/design/technica...

Software tools:

1. Get OneWireViewer from https://www.maximintegrated.com/en/products/ibutto...

• Download from above website
• Unzip and install the 1-wire driver

Program the 1-wire EEPROM:

1. Put it all together.

2. Go to "Start" -> "1-Wire Drivers" and run the OneWireViewer.jar.

3. In OneWireViewer, select DS2431 from "Device List" and then go to "Memory" -> "Banks" -> "Main memory" -> "Contents".

4. Edit the memory start at address 0x08 to 0xFB 0x30 0x36 0x35.

5. Click on "Commit Changes".

1. Unscrew the laptop to expose the DC jack.

2. Identify the space available around the DC jack.

3. Solder the DS2431 in place, don't forget to program it with correct data beforehand.

4. Reassembly the laptop.

5. Connect the alternative charger, no more annoying AC power adapter alert from the BIOS.