Disk Error 27

[Bob-Bob]

So I just got the Famicom Disk System that JessicaWolf sold me, and it powers on just fine. She included the RAM Adaptor, 6 batteries and a disk with Mario on one side and Mario 2 on the other side. However, after inserting the disk it loads for a while, then gives me the error number 27. Xious FAQ says that means its either a motor problem or a header problem. How can I determine which problem it is and what can I do to fix it? I doubt it's a motor problem as Jess repaired the Famicom herself before selling it, new belt and all. I hope it's not beyond repair. 

[JessicaWolf]

Just some background for anyone who might offer help. The disk was shipped in an electrostatic bag to help prevent any strange magnets from erasing or corrupting the disk. The system was tuned till I was able to get 100% reliability using 8 different disk from various sources (and I marked the position of the screw with a fine tipped marker). The belt was replaced less than a year ago and the system (except for when it was shipped) has remained in a cool climate controlled house.

[Voultar]

What condition was the felt pad of the pressure arm in?

I've found that to be the culprit in a lot of drives that have been properly aligned but still prove to be problematic.

[fredJ]

I've had this happen...
It is mechanical parts, and things can move around in shipping.
If you turned the little screw that is glued stuck it can move itself a little, but motor speed can also change a little... Adjusting the motor speed could fix the problem.

[Bob-Bob]

Jess already told me to very slightly adjust the screw in question (she even marked it before shipping so I could find it easily), but how do I adjust the motor speed? 

[fcgamer]

Is there somewhere else that shows pics or diagrams as to adjusting these screws and the like?  I also have a disk system, and keep getting this same error a lot, for no rhyme or reason.

[Bob-Bob]

I can link to the same article that Jess linked to me: http://www.famicomdisksystem.com/tutorials/fds-repair-mod/belt-replacement-adjustment/

It's a robust article on how to replace the belt and other adjustments, but the segment toward the end that says "Magnetic Head Tuning Method" is what she suggested I use to solve the Error 27 problem. Just remember - all you have to do is turn the screw veeeeeeeeery slightly.
Post Merge: July 13, 2014, 05:36:49 pm
An update:

On a complete whim today, I tried firing up the Disk System again. This time, the disk worked, but only one Side A (this side had Mario 2 on it). Side B (the side with Mario 1) however did not work (same error, Error 27). Jess has informed me that this is likely because that side of the disk went bad.

It's not a huge deal since I already have a Super Mario Bros. cartridge, but what exactly causes a disk/disk's side to go bad, and is there a way to fix it at all?

[P]

Either the drive is wrongly configured or the disk was written on a wrongly configured drive. But I guess it's also possible that the disk is dirty/damaged but I don't know.

[Voultar]

I can link to the same article that Jess linked to me: http://www.famicomdisksystem.com/tutorials/fds-repair-mod/belt-replacement-adjustment/

It's a robust article on how to replace the belt and other adjustments, but the segment toward the end that says "Magnetic Head Tuning Method" is what she suggested I use to solve the Error 27 problem. Just remember - all you have to do is turn the screw veeeeeeeeery slightly.
Post Merge: July 13, 2014, 05:36:49 pm
An update:

On a complete whim today, I tried firing up the Disk System again. This time, the disk worked, but only one Side A (this side had Mario 2 on it). Side B (the side with Mario 1) however did not work (same error, Error 27). Jess has informed me that this is likely because that side of the disk went bad.

It's not a huge deal since I already have a Super Mario Bros. cartridge, but what exactly causes a disk/disk's side to go bad, and is there a way to fix it at all?

If the disk/system was working fine prior to shipment, the only explanation for the disk not working is if it was introduced to a strong E.M. field during shipment.

So, side A is now working intermittently, and side B isn't working at all. Sounds like calibration, to me.