Hi,
Ergo and others will remember me trying to fix my CD 67SEMkII mid 2002. Well as usual I spend a long time over these things because often they get solved given enough time. My 67 suddenly died as the disc stopped rotating. Ergo and others helped a lot but I could not find the actual reason. Today I pulled it apart and tried again. No eye pattern - no rotation. Though I get reverse rotation in service mode.
After several minutes I got fed up and started pressing the track change buttons randomly and rapidly. Suddenly the display showed the disk time. I pressed play and it started playing.
What gives ? Stuck button? If so they would not operate in service mode - they did.
I checked all supply voltages and they seem fine. The +5V at the transport shows 4.96V while it is 5.08V at the regulator. When the disc spins the voltage at the connector drops to 4.67V.
The eye pattern is supposed to have a dc bias of 2.5 V and be 1.7V peak to peak. I get 1 V dc and 0.9 volts peak to peak.
Ergo, can you guess what happened? So should I do something to prevent it from stopping again? Laser current to be increased?
Its pretty tough doing that because the pot is under the transport.
Thanks.
Ergo and others will remember me trying to fix my CD 67SEMkII mid 2002. Well as usual I spend a long time over these things because often they get solved given enough time. My 67 suddenly died as the disc stopped rotating. Ergo and others helped a lot but I could not find the actual reason. Today I pulled it apart and tried again. No eye pattern - no rotation. Though I get reverse rotation in service mode.
After several minutes I got fed up and started pressing the track change buttons randomly and rapidly. Suddenly the display showed the disk time. I pressed play and it started playing.
What gives ? Stuck button? If so they would not operate in service mode - they did.
I checked all supply voltages and they seem fine. The +5V at the transport shows 4.96V while it is 5.08V at the regulator. When the disc spins the voltage at the connector drops to 4.67V.
The eye pattern is supposed to have a dc bias of 2.5 V and be 1.7V peak to peak. I get 1 V dc and 0.9 volts peak to peak.
Ergo, can you guess what happened? So should I do something to prevent it from stopping again? Laser current to be increased?
Its pretty tough doing that because the pot is under the transport.
Thanks.
Seems to me you are just one lucky guy 
As to what was wrong with the player, well it's really hard to tell. One reason for disc spinning backwards and player acting weird was no clock signal...
For CD67 it is impossible to adjust laser power it is automatic and done by TDA1307 (if I remember correctly).
I had a problem with my own player once that it didn't play CDR-s. It turned out that for some reason the TDA1307 (fixed gain device with gain of 1.7) did not have the gain needed for some reason. On scope it also showed some 0.7Vpp with CDR disc.... replacing the part cured the player..... If your's plays all the discs then leave it be, if not then I suggest try to replace TDA1307.
Ergo
As to what was wrong with the player, well it's really hard to tell. One reason for disc spinning backwards and player acting weird was no clock signal...
For CD67 it is impossible to adjust laser power it is automatic and done by TDA1307 (if I remember correctly).
I had a problem with my own player once that it didn't play CDR-s. It turned out that for some reason the TDA1307 (fixed gain device with gain of 1.7) did not have the gain needed for some reason. On scope it also showed some 0.7Vpp with CDR disc.... replacing the part cured the player..... If your's plays all the discs then leave it be, if not then I suggest try to replace TDA1307.
Ergo
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