on to DHO800's LiteOn PSU... (beware this is non-reversible invasive action to tear down)
only 3 wires to USB3 connector, black (gnd), blue?, red?. so what kind of PD is this? when not connected to DSO, blue is 4.11V, red is 0V, once connected whether on or off, blue is 1.68V, red is 15V. i tried $1.50 USB3 DC pigtail to power DSO from SMPS PSU... if 12V, current is 3A, if 15V, current is 2.37A during operation (at boot up , its half that). so its a preferable fact that PSU/DSO is not that complicated to handle/diy, fwiw...
Only 3 wires is acceptable, as only one CC is required
when terminated with a plug: it's up to the receptacle end to figure out which is active by terminating both CC1 and CC2 separately, each with a 5.1k pull down, and measure which one has a corresponding pull up, indicating it's the right CC line to negotiate capabilities and coordinate settings.
"Figure 2-2 illustrates the comprehensive functional signal plan for the
USB Type-C plug. Only one CC pin is connected through the cable to establish signal orientation"
(Ref for the nerds: USB Type-C Cable and Connector Specification Release 2.2, Section 2.1 pp 31-32
https://www.usb.org/document-library/usb-type-cr-cable-and-connector-specification-release-22).
Here's my LiteOn, together with a capture of the capabilities, captured with a Cypress CY4500 protocol analyser (hooked up to a PD trigger board) and corresponding scope traces. These were taken at PD trigger insertion.
I didn't take any current measurements, but I did measure the claimed voltage domains, and all were supported when I selected each one with the PD trigger.
The Cypress CY4500 is a very useful tool for PD debugging, it bridges the gap between a scope and LA as the protocol decoder on the CY4500 is generally more useful than any scope PD decoder I've encountered such as in the MSO3000T, unless you're interested in the weeds at the symbol level, as the CY4500 doesn't expose samples at high enough resolution in its time domain trace to be able to see the individual symbols (although it does decode perfectly).
Setting up the CY4500 software with the right firmware & software versions to begin with is a PITA: you need to install the original v1.0.0 PC software first to update the device's firmware, then install the V3 software as the V3 software doesn't recognise the device with earlier firmware.
https://community.infineon.com/t5/USB-EZ-PD-Type-C/CY4500-failed-to-detect-device-for-upgrade-firmware/td-p/332299