Famicom Disk System Head Adjustment - FIXED

[InsaneDavid]

I recently replaced the belt in my Twin Famicom using the tutorial at jfgoods.net. I put it all back together and had the usual success running my lone FDS game. Of course there were missreads here and there but I know that's part of the system and after a couple eject and reloads things were fine. However performance began to get progressively worse until I can no longer get the game to load. Error 27's and now error 21's up the ass. Every time - error 21.

I've run the drive with the case open and it appears as if everything is working right. Once a disk is inserted the head slips back to the outer edge of the disk, trips the switch, the drive resets (read light off / light on) and then smoothly moves back toward the center of the disk. It then retracts and tries again and that's when I get the error 21.

I'm curious if I have the disk set misaligned. The walkthrough above doesn't make it all that clear how to get it set right. From what I've gathered you turn the large gear wheel clockwise (looking at it from the bottom) until it will no longer turn. Then you loosen the set screw on the disk set, rotate it so the set screw is facing back at the head, then tighten it back down. The big thing I don't understand in the instructions is the difference in position of the disk set between pictures 41 and 42.

Can someone who has a properly tuned FDS take a picture of their drive in the default power off starting location of the disk set with the card holder removed? Am I missing a step somewhere or is there something I don't have set right? Something else to try? Any help would be great. Again, it did work after I changed the belt but has progressively gotten worse until now where I get an error 21 every time. Media is official Nintendo.