My VC4 from 2014 has been having reliably poor connection in the last couple years. When charging with 2A total, the current often drops by a huge fraction, sometimes down to zero. This seems to be a common problem from what I’ve read, and the issue seems to be the barrel jack having poor connection. Sometimes I can recover the current by twisting the barrel connector, and that’s how I managed for the past 2 years.
Today is the day that my patience finally ran out. Incidentally, a random type-C disco ball broke recently, which got me wondering whether it’s possible to replace the barrel jack with this spare type-C jack. The answer turns out to be yes, and here’s how.
First, one needs to open the charger and de-solder the barrel jack. This was the most challenging part of the entire mod; the trick is to use an iron to liquify (and pull on) one joint at a time. After iterating this a couple of times on all the joints, the jack eventually comes off:
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The barrel jack has an extra third pin that confused me, but that confusion was short-lasted when I tested and discovered that the extra pin (“switch pin”) is identified with the ground pin on the PCB.
Now, I desoldered the type-C jack from my other device and slightly reshaped it to make it fit:
It is important to note that this is a power-delivery only port, which has a reduced number of connections compared to a fancier data jack like the one in your phone. I read some stuff about how those fancier jacks require negotiation to determine the correct voltage, but in my case, I don’t have to worry about any of that because the charger accepts the 5V that my brick provides.
Now, I wire the type-C jack to the PCB. For mechanical support, I’m going to use nanotape to stick the jack’s PCB onto the front side of the charger PCB. The tape also serves the dual role of spacer, since the type-C jack is considerably shorter than the barrel. It took 6 layers of 1mm nanotape!
In retrospect, it would have been better to use something rigid to serve as spacer to avoid wiggle, but I couldn’t think of something at the moment. Here’s how it looks put together, with some cardboard added underneath for extra support.
Now dremel the casing to make a type-C-shaped slit, and put it back together. It works and does not experience current sag!
