MDX-C150 Adjustment

A reader has contributed some scans of the Sony MDX-C150 service manual and comments about adjustments he made to his unit.

Service Manual Sections


With recordable (MO) discs, MD unit was skipping when cold but would play when warm/hot. Premastered MDs did not exhibit problems.


After reading the manual I found that there are only two adjustments that are different for MO and premastered MDs: the focus and tracking. Looking at the circuit board diagram, I located the variable resistor for adjusting the MO focus bias. I put in an MD and put the player in test mode (which runs the laser continuously, as opposed to the normal, intermittent laser activity) and started playback. The MD was skipping badly, like a scratched CD. With a jeweler's screwdriver I then tweaked the resistor. I adjusted the focus bias until playback became clear, and that did it.

One note though, I have some Maxell disks (the new clear kind with powder blue lettering on the shutter) that still skip no matter what I do. All the Sony (even the old grey ones), TDK and some older Maxell (smoked plastic ones) all play fine. So there are some differences in the disks as well.

And cleaning the lens doesn't seem to help. Regarding the MD lens cleaner, been there done that.

Return to the MiniDisc Community Page.