I'm trying to build a Suzy Q Cable to debug a Chromebook, but I can't get it working.

The instructions are here.

What I have tried:

  • Opened the CCD state with the gsctool (the device supports Suzy Q debugging).
  • Swapped D+ and D-.
  • Re-soldered the breakout board with different USB A cables.

enter image description here

Edit: On the original cable schematic it looks like A8 and B8 is reversed? enter image description here

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  • \$\begingroup\$ You might need to connect all of the ground pins (A1, A12, B1, B12) \$\endgroup\$
    – MarkU
    Jul 30, 2022 at 3:09
  • 1
    \$\begingroup\$ The instructions say to connect A4, A9, B4 & B9 to your cable's VBUS, but you've only connected A4. As a result your resistors are not connected to your cable's VBUS either. \$\endgroup\$
    – brhans
    Jul 30, 2022 at 3:16
  • \$\begingroup\$ I have tried this as well (the pictures doesn't reflect this), but the contacts are also internally connected on the device port, so it might be not necessary. \$\endgroup\$
    – chrome
    Jul 30, 2022 at 3:17
  • \$\begingroup\$ The A5 to VBUS resistor is supposed to be 22k. I can't tell what you're used, but I don't see the 2 red stripes I would expect to see for a 22k resistor. \$\endgroup\$
    – brhans
    Jul 30, 2022 at 3:17
  • \$\begingroup\$ You also need to swap D+ and D- back - what you show in your pics doesn't match the instructions. \$\endgroup\$
    – brhans
    Jul 30, 2022 at 3:21

1 Answer 1


I found the problem, this breakout board is available as 'Male' and 'Female' version, the pcb silkscreen is intended for the socket version (female) so the plug version (male) is basically reversed.

enter image description here

The correct pinout for this specific breakout board is:

  • A5: D+
  • B5: D-
  • A8: 22K resistor to VCC
  • B8: 56K resistor to VCC

A fully working cable only needs the two resistors and the USB plug cable, additional joints for VCC/GND are not needed (at least on my device).

enter image description here enter image description here


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