"FPGA: ERROR: Unable to connect to USB/FT601 device" means your second PC can't reach the card's data link at all. Newer software says "Unable to connect to FPGA device" for the same thing. It's nearly always the port the cable is in, the data driver, or another program already using the card.
How to fix it
- The cable is in the JTAG port.
Move it to the data port. JTAG is only for flashing. Which is which is printed on the card. If yours isn't labeled, data is the port furthest from the gold strip. - The data driver is missing.
In MewTools open Drivers & Flashing and press Install DATA Driver (FTDI FTD3XX). Then Device Manager should show FTDI FT601 USB 3.0 Bridge Device with no warning. If you see FTDI SuperSpeed-FIFO Bridge instead, the driver isn't in yet. - Another program has the card.
Close MewTools and any other DMA tool. Only one program can use the card at a time. - The card has no power.
It gets its power from the main PC, so the main PC has to be on. If your card has a kill switch, it has to be on. Never flip it while the PC is on. - The cable or the port.
Use the cable from the box in a rear USB 3 port, with no hub. Flip the USB-C plug over at the card end.
Then cold boot the main PC and try again. Unable to connect and DMA card not showing have the deeper checks. Other errors are in DMA error messages.
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