Sharp MD-MS200 vs. A Concrete Floor

Duncan Chisholm ([email protected])

This is just a little story about a Sharp MD-MS200 MiniDisc recorder that tried to attack a concrete floor. For some pictures of the inside of an MS200 please see my Inside the MS200 article.

MS200 vs. A Concrete Floor

The floor won. Initially I was very impressed by how well the recorder stood up to it's fall onto a concrete floor. With the fall from my desk to a tiled floor it seemed to sustain no more damage than a few dents and scratches in the case. Playing was completely unaffected by the fall. As I discovered almost a week after the fall occured however, the recording ability of the MS200 was damaged. It would attempt to record without complaining, but when played back, the sound would cut in and out constantly and the track time display would not advance. When I tried to record on completely blank disks the TOC would be corrupted, and the the disk would be unusable thereafter (UTOC ERROR displayed on screen when disk inserted). Since I don't live in Japan, or know anyone who does, my chances of having the unit properly repaired were rather slim, so I opened up the case and started fiddling around a little bit.

Inside the MS200 (Part II)

Naturally, the first thing I inspected for damage was the record head. First let me explain how the record head is mounted inside the recorder. The magnetic record head and optical read/heat head are attached to each other, with one on either side of the disk, so that the magnetic head moves in unison with optical head. At all times the magnetic head should be positioned directly above the lens on the optical block, but it looked to me like it wasn't quite aligned properly after the fall. Because there didn't seem to be any adjustments for this alignment, I just bent the whole magnetic head arm back into a more suitable looking position. This was a rather gross adjustment when you consider the magnetic head itself is less than a millimeter across, so I wasn't really expecting it to help very much. Next I took a look at the optical head, more because I was curious about how it worked than because I thought it was the cause of my problem. I completely removed the optical block and poked around a little bit. This is the most impressive piece of engineering in the whole recorder!

After playing around with both the heads I put everything back together and tried it out. After everything I'd done to it, disks still played without a problem, but recording wouldn't work yet; I got a "LOCK ERROR" message. Incidently, I discovered a new function while I was testing out the recording of my MS200. All functions are disabled when the MS200 detects a UTOC ERROR, except the ERASE ALL function which allows you to overwrite the damaged UTOC. Pressing and holding the EDIT button will give you the prompt ALL ERASE?. Rather than damage the UTOC on all my disks to test the recording, I just repeatedly tried clearing the UTOC on the disk that had already been damaged.

I took everything apart again, looking this time at the locking mechanism, which is intended to prevent the disk from being removed when there's an impending TOC update. It turns out that the same mechanism is used to lock the eject lever and lower the magnetic head onto the disk surface. This means that if you record tracks and then play the disk before shutting of the recorder (which causes it to perform the TOC update), the head will remain in contact with the disk surface while playing. While the damage this causes to this disk and head is probably minimal, you may be able to increase the life of your recording head by always updating the TOC imediately after making a recording (which is a good idea anyway). I couldn't see anything wrong with the locking mechanism, so I just manually moved it through the cycle couple of times and put everything back together.

Yahh! Recording worked! After successfuly clearing the TOC on the damaged disk, I chose the main theme from Star Wars to be my first test recording, and it worked beautifully. Two weeks later, my MS200 is still playing and recording without any problem. The real test of whether or not everything is properly realigned will be trying to play disks that have been recorded on my MS200 on someone else's machine. I don't suspect this will be a problem though.

The moral of this story: Don't drop portable MiniDisc recorders! They're durable enough to take quite a lot of abuse, even durable enough to withstand having me poke around inside, but they're not invulnerable. I encourage other people to try taking apart their MiniDisc recorders, but don't start fooling around with the read/write heads like I did. This was the act of a desperate person! I'm still quite surprised that I was able to get it working at all.

Return to the MiniDisc Community Page.