# Repairing a PS/2 mini-DIN connection w/o clock pulses

I have a Fanatec CSR racing wheel with an optional sequential shifter. Since I last used them I lost the stock PS/2 cable and haven't been able to locate it. I bought an off-the-shelf PS/2 cable but found that only the upshifts on the sequential shifter works, not downshifts (up and down need to register).

I had a look inside of the shifter and the circuit is very simple. It has a square ps/2 female as shown on this page. The connections as shown, excuse the artistry

I am very inexperienced in electronics but this is the entirety of this device's circuitry so I would conclude there is no clocking.

Should all work fine by my approximation (and does for upshift). Examination of a female port as in the link shown above details that it connects to one of the NC pins of the mini-DIN format (left black wire in diagram), thus I am coming to the conclusion that the off-the-shelf PS2 replacement cable does not cater a connection for this pin, does that sound rational?

Edit: I have now solved the issue with the shifter in terms of physically managing to make it work. For anyone encountering a similar issue it transpires that if when looking at a diagram like this on a female connector, pins 6 and 5 are downshift and upshift respectively, each having +3.3V when wheel is powered. Grounding either 5 or 6 to pin 4 (ground pin) will cause an upshift/downshift event to register. My purchased cable and a faulty switch were causing the issue for me

• does that sound rational? ... yes, why manufacture a cable with unused wires ...... you may have to find one that has all the wires ..... here is the pinout pinouts.ru/Inputs/PS2Mouse_pinout.shtml ....... both of the pins next to the Vcc are unused, which means that the red wire is unconnected ..... you could just simply use another pin – jsotola May 28 '18 at 19:56

Examination of a female port details that it connects to one of the NC pins of the mini-DIN format, thus I am coming to the conclusion that the off-the-shelf PS2 replacement cable does not cater a connection for this pin. Does that sound rational?

"NC" in a pinout most often means "not connected" or "no connection."

It's fairly common for cable manufacturers to exclude wires for NC pins to save cost, so your assessment seems completely rational.

You will have to find a replacement cable that specifically lists being fully populated. Worst case you can get some connectors, sacrifice an old Cat5 Ethernet cable, and roll our own.

### EDIT:

Did some research and found a few vendors that at least appear to have fully shielded cables with all 6 pins wired through.

Kray Cables on Amazon carries 1ft, 6ft, and 10ft cables as well as extensions.

Digikey also carries at least one that has a mechanical drawing with wire color assignments for every pin.

• Thankyou, do you know how I would specifically find a fully populated cable, e.g: specific terms which signify it has all connections? I can only really find male-to-male on eBay now so I it is difficult to get concrete data on the product – Scott Anderson May 29 '18 at 14:20
• @ScottAnderson Unfortunately there isn't a standard way to express that, if it's mentioned at all. You just have to do some digging until you find a vendor that specifies it in some way. Edited the answer to include some options that look very hopeful. Good luck. – Phil C May 29 '18 at 15:04
• @ScottAnderson FWIW, the search terms I used to finally get a hit was "ps 2 cable 6 wired." Kind of a shot in the dark though after a few other attempts with different wording. – Phil C May 29 '18 at 15:08
• thankyou for your help – Scott Anderson May 29 '18 at 15:48