Hi EEVblog,
frankly I don't know if this topic was already handled and even the search function delivered to many results for me to check, so please apologize if this thread may be redundant.
I just ordered a new FY6900, and I informed myself about its issues, so I was prepared to replace the internal AC-DC-converter with a set of DC-DC-bricks to make it USB-C compatible.
Now I was pleasantly surprised after opening the case: The 6900-M version I received uses the AC-DC-PCB only for a PE-GND-earthed 5V-supply. If you supply power by the USB-B socket, the device already is fully functional and it reaches around +/- 8V at 50Ohm or +/- 12V at 1MOhm. Waveform peaks in the area of the voltage limit look a little disturbed, but anyhow it´s more than enough for many use cases.
So instead of a new power supply I only need a USB-C to USB-B converter
Please tell me if anyone wants pics...