Hi there,
I just bought an IBM 1391406 keyboard from a friend (who never used this keyboard), without the coiled cable. I just felt amazed for this vintage keyboard and I loved it in the first time; this is the keyboard I want to keep forever.
Then, I bought a cable on E-bay (which is a Datalogic CAB-365 Standard IBM PS/2 Mini-Din Wedge Coiled Cable); the cable seems to be compatible. Besides the cable, I also bought a Dual USB to PS2 Mouse and Keyboard Converter Cable Adapter, in order to use the keyboard in a USB Port in my computer.
Having all this set (keyboard + cable + PS2 to USB adapter), when I plug the keyboard in my computer USB port, I can't type anything. In the device manager, it appears as HID keyboard; it also appeared as barcode reader; according to Windows 10, the keyboard is working properly but, in fact, is is not working at all.
Do I need a driver or something like that to make it work in my computer? or is this just a matter of configuration that I'm not doing properly?