Dell PSU third pin fix

April 25th, 2014

A few years ago, I bought a PSU for my Dell D600 on eBay which turned out to be a really crappy Chinese pirate PSU which suffered badly from interference. When I wanted to fix the interference by connecting the plug to a different, and genuine Dell PSU, I stumbled upon a problem. All modern Dell PSU’s have a ID feature to confirm that the PSU is genuine, using a 3rd pin center pin connected to an EEPROM. If this chip does not match, the laptop won’t allow the battery to be charged. While a less scrupulous 3rd party manufacturer can nag one of those ID chips from a broken genuine Dell PSU and pass the test with a any poor quality PSU, I had to transplant this ID chip somehow, to make the PSU work.

New PSU cable splice New PSU cable splice

I recently got another Dell laptop with a broken PSU, which I could have if I could fix the PSU. Like last time, I decided to splice the cable with a board containing the chip.

Dell power adapter ID chip board

This board was made from veroboard, and ws a bit bulky, so I decided to design and order a new one. This posted is an illustrated guide to how this board is used.

Dell power adapter ID chip board

Read on…