Joonas Javanainen

Replacing a Super Famicom front panel flexible flat cable

I own an SFC (Super Famicom, “Japanese SNES”) that I use for running hardware tests on Super Game Boy and Super Game Boy 2 systems. My SFC has been modded with a SuperCIC mod so I can also use a PAL Super Game Boy with it. Unfortunately I got the SFC a fairly long time ago when I didn’t have that much experience with electronics and console hardware, so I was very sloppy and ended up damaging the unit in multiple ways.

Time for some SFC modding hall-of-shame photos!

SFC modding gore

CIC pads should not look like this after desoldering the chip
CIC pads should not look like this after desoldering the chip
Horror…none of these pins even need to be touched in this mod!
Horror…none of these pins even need to be touched in this mod!
The front panel flat cable doesn’t like it when you bend it like this…
The front panel flat cable doesn’t like it when you bend it like this…

Fixing my mistakes

Undoing the mainboard damage was straightforward: I just got a replacement board and redid the mod, but this time I was much more careful and had better tools available. For example, desoldering the CIC was much easier with hot air, and no pads were lifted.

Much better CIC desoldering result
Much better CIC desoldering result

The flat cable was another story: I only had a mainboard replacement and no other spare parts. After doing some measurements, I estimated the cable pitch to be 1.27mm. For some reason 1.27mm FFC parts are extremely rare, even on ebay and AliExpress. However, the cable is just a 11-way cable so I figured a 1.25mm pitch cable would only have a very small alignment error. I managed to find potentially suitable 11-way 1.25mm FFC parts, but they were out of stock! It looks like 11 signals is a very unpopular choice. In the end I decided to buy a 12-way 1.25mm cable from Digi-Key and try to mod it into a 11-way cable. A Molex 0982680177 cable seemed to be a good candidate.

The Molex cable was eventually shipped, and I found out that it fit nicely in the connectors on both ends after cutting a tiny bit off.

Cut Molex cable
Cut Molex cable

This particular cable is 6" (~15cm) in length, so it’s a bit longer than the original. However, there’s enough room in the case for the cable so it’s not a big problem. The length is not optimal but everything worked fine!

Final result with replacement cable installed
Final result with replacement cable installed

Conclusion

There you have it! If you ever need to replace a SFC front panel flexible flat cable, look for 1.25mm pitch FFC parts, and buy a 11-way cable or cut a bit off a 12-way cable.