2
\$\begingroup\$

I recently broke the male port of my USB-C laptop charger. I already got a new one, but I would like to fix and repurpose the old one to be the power for my Raspberry Pi 4 instead of throwing it out.

I ordered a 6 pack of USB-C male ports from Amazon thinking that it would be easy to solder it up especially that I am an electrical engineering student. I am now on the 6th try after knocking out some resistors, soldering the wrong pins, accidentally soldering pins together so I need to get this last one right.

My problem is that I don't understand what pins do what in this charger. The charger cable has red, black, blue, and white wires. The while and black wires are much thicker than the red and blues ones so I first assumed the following:

  • Red: Vcc
  • Black: GND
  • White: Data +
  • Blue: Data -

...but I am completely unsure if this is correct.

The fact that I get 0V across the red and black wires makes me even more uncertain than I already am. I'm guessing that there must be some enable wires (maybe CC) to tell a switch in the rectifier in the charger to start. But where do I connect it? How do I test it?

I used the image from Microchip in this link https://www.allaboutcircuits.com/technical-articles/introduction-to-usb-type-c-which-pins-power-delivery-data-transfer/ to try to figure out what might be what.

Please see the attached pictures for reference.

stripped wires of the charger

the charger

the new charger port (Has V, G, A1, A2, A3, A6, A7, B1 ...and 1C? labels)

\$\endgroup\$
12
  • 2
    \$\begingroup\$ That's just not answerable. The colors you depict are non-standard; even if they happened to coincide with the standard, you couldn't trust that. For a non-USB purpose, find the pair that has power, otherwise, probably forget it. \$\endgroup\$ – Chris Stratton Sep 10 '20 at 0:13
  • 1
    \$\begingroup\$ Yes, it defaults to 5v, ...if and only if it still works... \$\endgroup\$ – Chris Stratton Sep 10 '20 at 0:30
  • 1
    \$\begingroup\$ The thicker wires are more likely to be the power wires. \$\endgroup\$ – brhans Sep 10 '20 at 0:32
  • 1
    \$\begingroup\$ Based on your report, it's broken and you should recycle it. \$\endgroup\$ – Chris Stratton Sep 10 '20 at 0:53
  • 2
    \$\begingroup\$ Hi Raymond, welcome aboard. In addition to the useful comments above, It looks that you don't have the appropriate soldering tools and skill level to accomplish this. You should have in your soldering kit: liquid flux (in a little squeeze bottle) , some desoldering braid, a small solder sucker, some tip cleaner and brass wool, and some kind of "third hand" to hold the item. In this particular case, you would also find it helpful to terminate the cable on a small piece of perfboard, soldered to the shell of the USBC, then run the data wires across using tiny "wire-wrap" wire. \$\endgroup\$ – BobT Sep 10 '20 at 1:26
3
\$\begingroup\$

This should help you regarding what the wires were for in your original Dell charger cord.

My Dell power adapter (65W version) had a mechanical fault at the USB male connector shell (bent from internal PCB).

I cut open the Dell connector to check the wiring on the PCB at the USB-C connector. It has the same red, white, blue, black wires.

The labels on the PCB with the connected wire show (see attached pictures):

  • GND - black
  • VBUS - white
  • CC1 - blue
  • V+ID - red

I have the same type of replacement connector as you do. You need to take off the resistor R1 (this pulls up the CC line and makes it only power at standard USB 2.0 power and not PD). Solder the blue wire to the pad where the resistor was (the pad closet to the pins; the other side is connected to VBUS).

Dell USB-C connector PCB Wires red and blue

Dell USB-C connector PCB Wires white and black

\$\endgroup\$
3
  • \$\begingroup\$ Hey Chris, So glad this was finally answered. Here's a follow-up question though: what exactly is V+ID? Since then, I have purchased a new screw terminal connector to experiment. It only has V, GND, D+, and D- and no access to internal resistors can this not work? If not, why? \$\endgroup\$ – rayogunjimi Jul 13 at 2:20
  • 1
    \$\begingroup\$ As far as I can tell the V+ID is used to power the LED in the connector to show that the power is on. There is no need for this in your replacement connector, so the red wire is not needed. If you are trying to repair a power adapter line (as in the original post) and not create a data data cable then you need the CC line for supporting the Power Delivery protocol (selects the voltage and current). For a power adapter you don't need the data lines D+/D-. You need CC (blue wire for specific Dell power cable shown in the original and my Dell 65W version) to connect to the CC1 (A5) pin. \$\endgroup\$ – Chris Chase Jul 13 at 18:23
  • 1
    \$\begingroup\$ In the original picture of the replacement USB connector PCB, the A5 pin is connected to the R1 and R2 pads (the side closest to the pins). While small, I was able to solder the blue CC wire to that pad, after removing the R1 resistor (there is no R2 resistor present). The other side of R1 is connected to VBUS. And the other side of R2 is connected to ground. So on that connector type, when soldering the blue wire you need to avoid accidentally spanning the resistor gap to VBUS or GND (which I did in one solder attempt). I don't know if your specific replacement supports soldering to A5. \$\endgroup\$ – Chris Chase Jul 13 at 18:30
2
\$\begingroup\$

These colors are non-standard. Welcome to the bad news.

Black and white are clearly ticker than blue and red, your first bet would be white and black to be power. You can use a voltmeter to distinguish between +/- . If the power brick is plugged to the wall and everything "floats", the voltage between black and white should be around 5V. The white is probably +.

Red and blue are probably D+/D- and no one clearly knows who is who. The good news are you can try and the probability of frying something because of swapped D+/D- is low.

As a second try you may want to try red/blue to be CC1/CC2 (you are still almost OK to try both combinations).

And, there is still one more variant with pretty much high probability: there is some complex logic inside the original plug and red/blue are not USB signals at all. The cable does not look like an USB cable. The non-standard colors and the fact that you get 0v between the tick wires (black/white) hints in this direction also.

\$\endgroup\$
1
\$\begingroup\$

The White and Blue are not D+/D- wires. They are likely CC1 and CC2 wires. Try to solder them as such to your breakout connectors if you want the charger to operate in standard functionality.

If you want the charger to just output the default +5V, try to pull down one (or both) blue/white wires with 5.1k resistors to ground. Type-C ports/chargers enable default power only when they detect a presense of a device, which is 5.1k to ground on CC pins.

CORRECTION: from your picture and looking at the relative wire gauges, it looks like the White wire is VBUS power, and Red and Blue are CC wires. And yes, if the charger is not dead, red or blue wire should have some weak voltage source on them, to detect CC connection.

\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.