MD Walkman only plays pre recorded MD's

Recently acquired an MZ-R50 Walkman for $42 as a donor for parts. Described as working by the seller but I find that a broad claim when buying ex Japan. I noticed it was fine playing a pre recorded MD but started to skip and stop reading any MD recorded on other units. Then I flipped it over and it played any MD right through without Disk Err message popping up. Reminds me of the notorious issue with the D350 Discman which only plays when held at 45 degree angle. In that case it's the spindle motor main bearing wear. The MD problem I thought was lack of power on the Laser unit as it requires more power for non reflective surfaces on recordable MD's to get reliable reads and transfer to the DAC. However before dismantling and attempting to adjust the Laser pot if you have an MD not playing recordable media I suggest the flip test. If the Walkman plays its not Laser power that is the problem but most likely the flimsy plastic guide that supports Laser transport. These tend to sag over years of non use and it's enough to interfere with the focus of the Laser on the disk surface. Flipping the Walkmsn over seems to negate the effect of gravity on this guide restoring focus and allowing the recordable media to play correctly. So wondering what the fix involves to restore normal functionality when this fault occurs. Many others I am sure have this issue with MZ-R30 and MZ-R50 recording MD Walkman.

 

I haven't decided how best to fix the problem if it is indeed the effect of gravity long term on that plastic guide that is part of the Laser assembly. So far storing it for a few days inverted has not rectified the problem. Maybe longer term it would have some effect. If it's more to do with the degeneration of the plastic over time it's probably not going to matter how you store the Walkman. Only replacement of the laser block will restore it and of course any assembly you acquire from the same model donor MD Walkman might not be any better.

 

There is no evidence of lubrication and given the proximity to the Laser lense I doubt any could be used. It seems yet another case of plastic fatigue to go with DD Walkman CG, D250 Discman central gear and small reel gear in WM-D3 Walkman Professional. Ugh...plastics!!

 

I seem to recall this problem being discussed some time ago on minidisc.org. It may be the spring bracket for the optical block.