USB-C power mod for the T440p

[MrDale93]

Hello again,

I'm not 100% sure I've chosen the right category to post this in, so if not please use some of that admin magic and move it to where it needs to be.

If you have previously done work on repairing or replacing ThinkPad charging ports I'd appreciate some feedback on this post. You'll know more than me when it comes to this.

As I stated in my last post I have a T440p and I want to mod this to the point where (almost) everything is custom to some degree. I'll be keeping the original chassis, case, all of that this is just hardware. I've done a couple of things so far and I'm happy with the results. One of the things on my to do list is swapping the original charging port for USB-C. My reasoning is that the laptop is 11 years old at this point, meaning the charging port is more than likely also 11 years old too, unless the previous owner had it replaced for whatever reason which I highly doubt. As a bonus if the charging wire I have now breaks in the future it will be much easier and cheaper to get a new type C cable than a proprietary cable from some eBay seller, or paying a premium on a replacement from Lenovo themselves.

I know that it is possible to swap to USB-C on some models, there are posts online on different sites from others who have done this to similar models, but nothing I can find about this model specifically although I would imagine it is doable. I dont mind some difficult work if needed, that just adds to the fun.
I am capable with electronics having built multiple desktops, stripped and rebuilt many laptops and done enough work on handheld games consoles and guitars to know at least some of what not to do, however I have no experience working directly on a power port. Because of this I want to figure out and also understand a few things before committing to the task.

In my research I have found:

• The amperage of the AC adaptor should be equal to or greater than what the laptop requires.

• The USB-C module chosen as a replacement must also support 20V charging.

• The laptop has something called a 'sense' wire, allowing the identification of the charger as a charger, determining the power capabilities of the charger by wattage & this could make the replacement more complex.
  An easy workaround for this is to ensure this is not connected to the new USB-C module and isolated with electrical tape or heat shrink tubing, and secured so it cannot move inside the chassis of the laptop and come in contact with other components.

It wont be hard to find a module to use for this purpose, and I'd imagine it will be very cheap too. I know I'll also need to have some bracket made up to fit around the C shape port too as it is quite a bit smaller than the original plugs footprint and a large gap going all the way around the port itself will annoy me greatly. There are a few places I can get things 3D printed sol Ill probably go with that, either in the ThinkPad grey, or the silver colour from the Lenovo logo, or maybe even the same as the red from the Touch point as long as it will be thin enough. A decent little hidden accent colour that you'd only notice if you looked for it.

Finally, I have run out of solder so I will be getting some lead free rosin core solder with a diameter of 0.5mm to do the job. That's probably worth mentioning too.

I think that just about covers everything for this mod, is there anything I am missing or should know about? I am well aware there are risks to this type of work that could involve anything from incompatibilities, shorts, or the laptop becoming a fire hazard if done incorrectly so I will be 'checking twice cutting once' throughout the process. Please let me know of anything I have forgotten or got wrong.