Hi All
Got one of these off ebay but it will not record (seller gave me partial refund as requested by myself). Plays fine. A common issues but not many solutions other than a new overwrite head (stupidly expensive if that is the issue). If you record it will not playback anything although it goes through the motions. It does not write to TOC even though it says it does.
The mechanism works fine. Greased everything and cleaned everything (including the three motors). Is it worth adjusting laser power temp which is can be done via service menu? Discs do not get warm as they do on my SONY deck?
It is very solidly built and does have a great sounding DAC and it can be used as an input device for other digital sources.
Any help would be appreciated. Would love to get it working just for the fun of it. One person suggested running it for a hundred hours to get it moving again!
Got one of these off ebay but it will not record (seller gave me partial refund as requested by myself). Plays fine. A common issues but not many solutions other than a new overwrite head (stupidly expensive if that is the issue). If you record it will not playback anything although it goes through the motions. It does not write to TOC even though it says it does.
The mechanism works fine. Greased everything and cleaned everything (including the three motors). Is it worth adjusting laser power temp which is can be done via service menu? Discs do not get warm as they do on my SONY deck?
It is very solidly built and does have a great sounding DAC and it can be used as an input device for other digital sources.
Any help would be appreciated. Would love to get it working just for the fun of it. One person suggested running it for a hundred hours to get it moving again!
Definitely do not alter the laser power at this stage. Minidisc work on the Kerr Magneto Optical effect. The magnetic head is what does all the work during recording of changing the disc structure to be a 0 or a 1, the laser simply heating the point of the disc that is to be written to.
First checks have to be on the head. Check its continuity back to the PCB and look with a scope during recording that there is 'something' going on as regards drive signals.
I'm not familiar with the Yamaha but imagine it could be similar to Sony models where the laser power current set during manufacture is written to NVM (non volatile memory) and testing involves calculating laser current and comparing to this value. This is done for both record and play modes, record mode laser output is very high relative to what we are used to in CD players and so on at around 7mw.
At the end of the day it could well be the pickup but just don't assume it is without first checking all the other stuff. The magnetic head distance from disc is fairly critical as I remember but may not be adjustable.
First checks have to be on the head. Check its continuity back to the PCB and look with a scope during recording that there is 'something' going on as regards drive signals.
I'm not familiar with the Yamaha but imagine it could be similar to Sony models where the laser power current set during manufacture is written to NVM (non volatile memory) and testing involves calculating laser current and comparing to this value. This is done for both record and play modes, record mode laser output is very high relative to what we are used to in CD players and so on at around 7mw.
At the end of the day it could well be the pickup but just don't assume it is without first checking all the other stuff. The magnetic head distance from disc is fairly critical as I remember but may not be adjustable.
The most common issue is damage to the write magnet above the head. The laser must be working as it is reading the disc and as Mooly suggests, DO NOT ATTEMPT TO ADJUST THE LASER POWER! You will write off the head.
A new assembly is probably required. Setting up is automatically performed as are the self test measurements for the uProcessor to calculate the adjustments needed.
A new assembly is probably required. Setting up is automatically performed as are the self test measurements for the uProcessor to calculate the adjustments needed.
Update
Got it to work momentarily by putting a screw drive on top of the write head. It played back the few seconds of the track I recorded and even wrote the TOC. When I reloaded it had a UTOC error which was progress but another MD could play it!
I tried bending the write head assmbly slightly to get it to work but no luck I am afraid. I suppose it has to be just right! My theory is that the plastic parts of the assembly may deform over time perhaps.
Got it to work momentarily by putting a screw drive on top of the write head. It played back the few seconds of the track I recorded and even wrote the TOC. When I reloaded it had a UTOC error which was progress but another MD could play it!
I tried bending the write head assmbly slightly to get it to work but no luck I am afraid. I suppose it has to be just right! My theory is that the plastic parts of the assembly may deform over time perhaps.
Before you start bending anything, first measure the continuity of the head from the PCB it plugs into. You could have a break somewhere in the flexible ribbon at the head.
Hi. No voltage from board wires to magnetic head so could be a loose connection. Decided to leave it for now as at the moment I have a very good sounding MD player / DAC and have 2 other functioning Sony recorders. May try another repair if the Sonys fail.
Mechanisms are definately the weak point in MD. Previously had a Technics deck that would not load an MD at all. In fact the 2 Sonys I have I treat with kid gloves loading the disc just in case! I have an MDSJE640 from new and had to replace the eject mechanism drive belt recently. Rant over!
Mechanisms are definately the weak point in MD. Previously had a Technics deck that would not load an MD at all. In fact the 2 Sonys I have I treat with kid gloves loading the disc just in case! I have an MDSJE640 from new and had to replace the eject mechanism drive belt recently. Rant over!
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