[EE]:: Chromebook psu cable colours / functionality

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[EE]:: Chromebook psu cable colours / functionality

RussellMc
Getting older / lazier. I have pulled apart much. Sometimes someone may
know what it takes to save some hours playing ultimately for a $45 product.
Some (possibly) useful links at end.

- Chromebook psu with damaged USB-C plug
- Sought to add an after market lead - 4 wire and no colour matching.
- 3 wires from psu where standard is four
- Fully non standard colours
- Indication are that voltage negotiation requires correct end to end
connection.
- Voltages and response to resistor "programming" matches no obvious proper
result.

Q1 how do the 3 non std wires connect to a std cable and colour code?
Q2 Is it dead Jim?
Q3 Who owns the zebra?

It's not my device. Given psu voltage agility destruction is a possibility.
Not hacking it open would be nice.


_____________________________________________________

I unwisely offered to swap the damaged USB-C end on a Chromebook power
adapter (used by a niece).
Delving into the damaged USB-C connector should answer my questions but
damage and tininess and time make this undesirable.
I could acquirte/make a USB-C breakout socket but a new adaptor costs $45
and ... .

How hard can it be?
The Chicony A18-0N45N1A adapter claims to be capable of 5 9 12 15V at 3A
and 20V at 2.25A
Voltage selection for various 5V/ XA ratings is typically by resistor magic.
A table covering multi mode voltages advises "Chip" in the selection column.
ie it seems likely that the adapter requires the correct wires to be
connected to the chromebook and it negotiates output.
Therein lies the problem

Chromebook psu cable is Black Blue White.
Standard USB C power leads are 4 wires and usually Blk Red Wht Grn or Org
Wht Grn Blu.
ie Positive is black or white. Blue is absent.

Voltages are low and vary interestingly with various resistors and
shortings - but never in any way usefully.
The suggested 5.1K to ground (target is present) and 51k to high (high
current mode) appropriate in simpler modes cause changes but voltages
between leads are small (Under 2V, may be zero between non shorted pins)

I have had no practical experience of USB-C powering.
A USB-C supply requires a pull down resistor from the CC lead to ground to
activate the supply and then may require a pul;lup resistor to change into
high voltage modes.

The adapter seems sealed for death. A dremel would cure this. It may not
solve the problem.

________________________________

Interesting links along the way:
No strong order or guaranteed usefulness. Items towards top MAY be more
useful.
Quite a good black hole.


USB Type-C Cable and Adapter Tips and Tricks
<https://www.chromium.org/chromium-os/cable-and-adapter-tips-and-tricks>

Termination Resistors Required for the USB Type-C Connector – KBA97180
<https://community.cypress.com/docs/DOC-10779>

USB Type-C Verification: Challenges and Solution
<https://verificationacademy.com/verification-horizons/november-2016-volume-12-issue-3/USB-Type-C-Verification-Challenges-and-Solution>

ST TA0357 - Overview of USB Type-C and Power Delivery technology
<https://www.st.com/resource/en/technical_article/dm00496853-overview-of-usb-type-c-and-power-delivery-technologies-stmicroelectronics.pdf>

SE EE - Why would a USB-C adapter have a pull-up resistor?
<https://electronics.stackexchange.com/q/446528/3288>

 Pinouts and signals
<https://www.aggsoft.com/usb-pinout-cable/usb3-type-c.htm>
USB C resistor values search
<https://www.google.com/search?rlz=1C1CHBF_enNZ834NZ839&sxsrf=ALeKk00iOHBJuMJqd2nyPhZLb360c-4TcA%3A1609735416671&ei=-JzyX9bCKMXUz7sP2IeIyAQ&q=usb+c+resistor+values&oq=isbc+resistor&gs_lcp=CgZwc3ktYWIQARgBMgcIABDJAxANMgQIABANMggIABAIEA0QHjIICAAQCBANEB4yCAgAEAgQDRAeMggIABAIEA0QHjIICAAQCBANEB4yCAgAEAgQDRAeMggIABAIEA0QHjIICAAQCBANEB46BAgAEEc6BQgAEJECOggIABCxAxCDAToLCC4QsQMQxwEQowI6AggAOgUIABCxAzoECCMQJzoICAAQyQMQkQI6BAgAEEM6BQguELEDOgcIABDJAxBDOgQILhBDOgUIABDJAzoICC4QxwEQrwE6DgguEMcBEK8BEMkDEJMCOgQIABAKOggIABAWEAoQHjoGCAAQFhAeOgUIIRCgAVDfqfsBWObG-wFgm_D7AWgAcAJ4AIABkwKIAacUkgEFMC43LjaYAQCgAQGqAQdnd3Mtd2l6yAEIwAEB&sclient=psy-ab>
Same - images
<https://www.google.com/search?q=usb+c+resistor+values&rlz=1C1CHBF_enNZ834NZ839&sxsrf=ALeKk00Bwz7MCj-UUBrQlOzDh1EEMp1ioA:1609739544615&tbm=isch&source=iu&ictx=1&fir=I4_lOX1pNiSM-M%252CMDpp9aKiEFrqNM%252C_&vet=1&usg=AI4_-kTWShDJyu6ixskUoACglqiKSMTAkA&sa=X&ved=2ahUKEwi_7vKNy4HuAhUX9nMBHQpiBp0Q9QF6BAgZEAE&biw=2340&bih=1152#imgrc=I4_lOX1pNiSM-M>
    Image subset
<https://www.google.com/imgres?imgurl=https%3A%2F%2Fmicrochip.wdfiles.com%2Flocal--files%2Fusb-i%3Acable-connection%2Forientation.png&imgrefurl=https%3A%2F%2Fmicrochipdeveloper.com%2Fusb%3Atc-pins&tbnid=Zadt9YE0VkzeKM&vet=12ahUKEwitvumz6YHuAhW8M7cAHYFuAtcQMygGegUIARCwAQ..i&docid=VKXJ3ADGMtiuZM&w=918&h=577&q=usb%20c%20resistor%20values&ved=2ahUKEwitvumz6YHuAhW8M7cAHYFuAtcQMygGegUIARCwAQ>
    Image subset
<https://www.google.com/imgres?imgurl=https%3A%2F%2Fmicrochip.wdfiles.com%2Flocal--files%2Fusb%3Atc-pins%2Fvconn.png&imgrefurl=https%3A%2F%2Fmicrochipdeveloper.com%2Fusb%3Atc-pins&tbnid=HAk868Pbzw8tNM&vet=12ahUKEwitvumz6YHuAhW8M7cAHYFuAtcQMygPegUIARDCAQ..i&docid=VKXJ3ADGMtiuZM&w=1245&h=477&q=usb%20c%20resistor%20values&ved=2ahUKEwitvumz6YHuAhW8M7cAHYFuAtcQMygPegUIARDCAQ#imgrc=HAk868Pbzw8tNM&imgdii=flwGn5ItvqdVSM>
    Similar - with FT232 image
<https://www.google.com/imgres?imgurl=https%3A%2F%2Fkicad-info.s3.dualstack.us-west-2.amazonaws.com%2Foriginal%2F3X%2F2%2F6%2F2658c42dacf38c694f39a472971a274ff3ef5a91.png&imgrefurl=https%3A%2F%2Fforum.kicad.info%2Ft%2Fhow-to-connect-a-ft232rl-to-a-usb-type-c-connector%2F18557&tbnid=r6nRef8jdnP2gM&vet=12ahUKEwitvumz6YHuAhW8M7cAHYFuAtcQMygUegUIARDMAQ..i&docid=31bslp7DIwWPBM&w=688&h=716&q=usb%20c%20resistor%20values&ved=2ahUKEwitvumz6YHuAhW8M7cAHYFuAtcQMygUegUIARDMAQ>

How to connect a FT232RL to a USB type C connector
<https://forum.kicad.info/t/how-to-connect-a-ft232rl-to-a-usb-type-c-connector/18557>

Images - type C charger wiring diagram
<https://www.google.com/search?q=type+c+charger+wiring+diagram&tbm=isch&bih=1152&biw=2340&rlz=1C1CHBF_enNZ834NZ839&hl=en&sa=X&ved=2ahUKEwitvumz6YHuAhW8M7cAHYFuAtcQrNwCKAJ6BQgBENkB>

USB power delivery <https://microchipdeveloper.com/usb:power-delivery>





*lowish <https://turbofuture.com/computers/Color-Coded-Wire-inside-the-USB>*

web search
<https://www.google.com/search?rlz=1C1CHBF_enNZ834NZ839&sxsrf=ALeKk00_G8xFa1QYMv2m-9IF7tnPVgznEg%3A1609734521868&ei=eZnyX9bANKuV4-EP5OGfsAI&q=usb+3+wire+colors+and+functions&oq=usb+3+wire+colors+and+functions&gs_lcp=CgZwc3ktYWIQAzoECAAQRzoECCEQClDPvIMLWKDqgwtgl_mDC2gDcAF4AIABmQKIAdAJkgEFMC40LjKYAQCgAQGqAQdnd3Mtd2l6yAEIwAEB&sclient=psy-ab&ved=0ahUKEwiW4e6yuIHuAhWryjgGHeTwByYQ4dUDCA0&uact=5>
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Re: [EE]:: Chromebook psu cable colours / functionality

William Westfield

> Voltage selection for various 5V/ XA ratings is typically by resistor magic.

Are you sure?
I thought older USB was via resistors, but that the new USB-C stuff involved software-level negotiation, sort-of like PoE.

BillW

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Re: [EE]:: Chromebook psu cable colours / functionality

William Westfield
>
> I thought older USB was via resistors, but that the new USB-C stuff involved software-level negotiation, sort-of like PoE.

Since I now have a charger of my own to fix, I investigated this more thoroughly.
Negotiation IS required to get the higher voltages/higher power delivery, but it uses a separate (non-USB) conversation on the CC signal.  CC signaling is WRT the GND connection.
(This is different than the 4-wire V+/GND/DM/DP scheme, where pull-up/down resistors on the data lines would mean ‘something.’)


A three-wire power-supply-only cable is “extremely likely” to consist of V+ (red), GND (black), and CC (blue, in my case?)

Pretty nice presentation:

https://web.archive.org/web/20161220102831/http://www.usb.org/developers/presentations/USB_DevDays_Hong_Kong_2016_-_USB_PD.pdf <https://web.archive.org/web/20161220102831/http://www.usb.org/developers/presentations/USB_DevDays_Hong_Kong_2016_-_USB_PD.pdf>

CC also apparently controls the “alternative pin function switching” and perhaps “other stuff”, so the protocol used is relatively complex.  (Assuming that everything is actually conforming to the USB 3.2 specs…)

Sigh.  Rant: Back in the bad-old-days, computers were connected with rs232, and if you had a problem, it was practically “always the cable.”  Wrong gender on one end or the other, wrong DCE/DTE-ness somewhere (crossover or not), not all necessary signals were actually connected from one end to the other (cables varied from 3 to 26 conductors), etc.  USB came along to fix all of that.  ONE standard cable with obvious “host” and “device” sides.  It was all good up until USB3.  And now we have to worry about connector types on each end, how many signals are actually implemented in the cable, and even whether the wires are thick enough.  Progress :-(

BillW

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Re: [EE]:: Chromebook psu cable colours / functionality

mailinglist4

On 2021-01-26 16:38, William Westfield wrote:

>> I thought older USB was via resistors, but that the new USB-C stuff involved software-level negotiation, sort-of like PoE.
> Since I now have a charger of my own to fix, I investigated this more thoroughly.
> Negotiation IS required to get the higher voltages/higher power delivery, but it uses a separate (non-USB) conversation on the CC signal.  CC signaling is WRT the GND connection.
> (This is different than the 4-wire V+/GND/DM/DP scheme, where pull-up/down resistors on the data lines would mean ‘something.’)
>
>
> A three-wire power-supply-only cable is “extremely likely” to consist of V+ (red), GND (black), and CC (blue, in my case?)
>
> Pretty nice presentation:
>
> https://web.archive.org/web/20161220102831/http://www.usb.org/developers/presentations/USB_DevDays_Hong_Kong_2016_-_USB_PD.pdf <https://web.archive.org/web/20161220102831/http://www.usb.org/developers/presentations/USB_DevDays_Hong_Kong_2016_-_USB_PD.pdf>
>
> CC also apparently controls the “alternative pin function switching” and perhaps “other stuff”, so the protocol used is relatively complex.  (Assuming that everything is actually conforming to the USB 3.2 specs…)
>
> Sigh.  Rant: Back in the bad-old-days, computers were connected with rs232, and if you had a problem, it was practically “always the cable.”  Wrong gender on one end or the other, wrong DCE/DTE-ness somewhere (crossover or not), not all necessary signals were actually connected from one end to the other (cables varied from 3 to 26 conductors), etc.  USB came along to fix all of that.  ONE standard cable with obvious “host” and “device” sides.  It was all good up until USB3.  And now we have to worry about connector types on each end, how many signals are actually implemented in the cable, and even whether the wires are thick enough.  Progress :-(
>
> BillW

If useful, by far the best video I've ever seen to quickly describe how
'fun' USB charging is:

https://youtu.be/1nx_n-wEtII

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