You don't need any special discs for alignment. There are are only two waveforms you see... that when playing a track and the "silence" or inter track space between tracks. Every disc gives the same pattern. The official test discs do have a known reflectivity and in practice 99.8% of commercial CD's meet that standard. Just never use a CDR or CDRW.
Mods... has to be worth looking at the analoge stages/muting and opamps.
Can you adjust the laser to the right voltage with only a multimeter? I have a Pioneer PD-S503 I have fiddled with the radial read on disk screw on the laser cart and iot reads fine. At first the lense eye has fallen of, cleaned it, dry cleaned it, glued it back in place, fiddled with the rad. read screw and reads everything now just fine and dandy. Forgot to say, sorry, that in did not read especialy only track 1 from disck, it skipped, skipped, skipped and afterwards dead spin untill disk could be played again with alittle more, till the player could be turned off from the power off key. I am talking about the 0,8V CDR and 1,2V original CD laser power adjustment method.
Hi oszkar,
I've seen your other thread
but tbh you need the correct equipment and more of an understanding of what all the adjustments do.
All you can do with a meter is deduce the laser current (by ohms law and the volt drop across a low value resistor that should be present in the laser power circuitry). It doesn't tell you anything about the quality of the signal coming off the disc. If the lens has had to be refitted then even a few microns misalignment [might] be crucial. Increasing the laser current will increase the amplitude of the signal recovered from the disc but usually if that improves or corrects a problem then often there is another underlying issue.
I've seen your other thread
but tbh you need the correct equipment and more of an understanding of what all the adjustments do.All you can do with a meter is deduce the laser current (by ohms law and the volt drop across a low value resistor that should be present in the laser power circuitry). It doesn't tell you anything about the quality of the signal coming off the disc. If the lens has had to be refitted then even a few microns misalignment [might] be crucial. Increasing the laser current will increase the amplitude of the signal recovered from the disc but usually if that improves or corrects a problem then often there is another underlying issue.
The lense had the old glue point, 4 of them in total it wasen't moving not a dust messure right or left. The player had a good life, no abuse in any way. I am aware of the Oscilator thing and all steps test pins if I had one I have had done the job! Anywho, all that I am saying in the end is that no other screw was touched as I knew of this problem so I went straight to the point and the problem as expected, was solved, only that I am wondering wich pot sould I adjust so that there wouldn't be any overcurent!
I'm not quite following what you mean but the "laser power pot" which is usually on the pickup itself is the only one that affects the laser current. No other pot in the player does.
That pot is factory set using a laser power meter to measure the optical light intensity emitted. On Sony pickups the value of current that has been set is recorded as part of the pickup serial number. That's why its easy to check on those types.
Grease (which has to be the right sort and viscosity) is normally applied to the sliding parts of the pickup and any worm gear drive but only very sparingly.
This might help you understand some of the adjustments generally,
http://www.diyaudio.com/forums/digital-source/226288-sony-cdp790-kss240-restoration-project.html
That pot is factory set using a laser power meter to measure the optical light intensity emitted. On Sony pickups the value of current that has been set is recorded as part of the pickup serial number. That's why its easy to check on those types.
Grease (which has to be the right sort and viscosity) is normally applied to the sliding parts of the pickup and any worm gear drive but only very sparingly.
This might help you understand some of the adjustments generally,
http://www.diyaudio.com/forums/digital-source/226288-sony-cdp790-kss240-restoration-project.html
To answer this thread here and not posting anything else here anymore, the player of this thread that is in question here should be sent in service at a dealer, I have sent my PD-7700 with a new laser in it that did not read at all and test cd fixing, laser pots, board pots and other serviceing for pots adjustment into the entire player that could have been adjusted as i have asked on the box that I have sent it in, costed me 70 euros and it worked just fine. It took 2 days to have it repaired, than I was contacted by telephone and told the repair operations performed and price!
I'm late to this forum but I always use a Mobile Fidelity disc for alignment. I came to this conclusion awhile ago when measuring voltage of laser diode when playing different discs. These discs measured in middle of voltage levels I measured so I believe they are probably most consistant set to redbook standard. I am also able to play the wider range of discs when aligning to a MF disc.
Hi Chris, I am going to buy a test CD set, I did some search online, and I get information that the test CD5/5A is SBC426/426A, do you know what the difference is from SBC444/444A? only 444/444A is available for sale now. Thanks.
-Jerry
Hi Chris, thank you reply me. The Philips test discs are rare on sale, I just found a set SBC444/444A that will cost 150 EUR. I repair vintage Philips CD players, especially CDM0/CDM1, I think this is a useful tool for adjustment, so want to buy a set. I read your reply to someone that the 444 is the upgrade version of 426(5/5A), hope it is good for my hobby.