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Old 14th September 2012, 05:41 AM   #11
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Quote:
Originally Posted by fandik View Post
No, after replacement of big PS caps and 5x33uf caps in laser drawer, still no improvement.
Well, now that those are eliminated, thinking about it some more, I think it fairly possible that you have a simple adjustment issue. The most common issue with the CDM-0 mech used in the B225 is wear of the platter motor thrust bearing. As it wears, the platter height drops, so the bearing is adjustable, via a #10 Torx driver hole in the bottom side of the bearing. If it is on the borderline of too low platter height, I could very definitely imagine it losing tracking lock momentarily when it shifts to track search mode. The best way to dial it in without an oscilloscope is to play a cd-r disc(which it should be able to play) with the player "up on blocks", so you can adjust while playing, then turn the bearing clockwise slowly until it starts to lose track, then counterclockwise until it loses track again, then set to the midpoint between these points. Once set to a point where it has no more troubles with any disc, use a bit of glue around the bearing thread to lock it in place.
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Old 14th September 2012, 07:35 PM   #12
fandik is offline fandik  United States
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Haik, yes, I wish it would be that simple Thanks!
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Old 14th September 2012, 07:41 PM   #13
fandik is offline fandik  United States
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Stephen, thank you for your suggestion! Few questions on this one - is it described in the SM? I have it downloaded, maybe I missed, I did not print all of it. Second - I do have a scope if it will make it easier to do. Problem with most adjustments that they require test CD to begin with. And third one - what do you mean "on the blocks"? Does whole mech somehow has to come out?, there is no hole to access it from the bottom in the frame.
Thanks again,
Leo
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Old 15th September 2012, 05:31 AM   #14
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Quote:
Originally Posted by fandik View Post
Stephen, thank you for your suggestion! Few questions on this one - is it described in the SM? I have it downloaded, maybe I missed, I did not print all of it. Second - I do have a scope if it will make it easier to do. Problem with most adjustments that they require test CD to begin with. And third one - what do you mean "on the blocks"? Does whole mech somehow has to come out?, there is no hole to access it from the bottom in the frame.
Thanks again,
Leo
Strangely, while the thrust bearing adjuster is identified, as "axial adjustment screw", the SM is missing any mention of adjusting it. However, it does tell you how to get under the mech & how to play a disc while the mech drawer is in the needed out position. You don't need a test cd. You just need a couple or few burned cd-r discs & a cd or two. You should see the classic "eye pattern" on the "HF" line, with pin7 of the SAA7010 chip being one easy place to tap it. Just maximize the amplitude of the waveform with a cd-r, then check with several other discs & make sure you get the best compromise adjustment if there is any variance.
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Old 17th September 2012, 03:22 PM   #15
fandik is offline fandik  United States
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Thank you! Will give it a try
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Old 20th September 2012, 08:31 PM   #16
fandik is offline fandik  United States
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Well, maybe I'm crazy, but I don't see any difference when I'm trying to adjust spindle motor bearing. To start with I don't see T10 torx there - it's much smaller ferrite-looking hex with about 5mm contra-nut. It does not seems to have any effect not on playing CDr nor on oscilloscope pic. I even tried to remove it completely. Am i adjusting something totally different? I feel stupid
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Old 21st September 2012, 02:31 AM   #17
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That sounds like you're describing the radial tracking motor bearing assembly. I can't recall ever seeing any early Philips platter motor with a nut-locked thrust bearing. Went back to the manual, and it looks like you must have the VERY early mech shown in fig 4.13, not the CDM-0 shown in 4.14. Still, if you loosen the locking nut, then adjust the bearing, you should the the HF patter amplitude go up & down. The focus servo will track it to a certain point in each direction of turning, so the turning range will be something like +/- 2 turns, in which you then find the "happy medium" center of that range. However, being at least a decade or more since I have seen such an early mech, it may behave differently than a CDM-0 in that regard.
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Old 28th September 2012, 12:32 AM   #18
fandik is offline fandik  United States
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Sorry, did not have time to work on it. As weird as it is - it's probably platter/spindle motor that I was trying to adjust. Tracking motor is a swinging assembly with laser which moves along cut-out. It has about 1/4" nut in the middle of aluminum bar with 2 hex on the sides. I can't attach any pics in here, can I?
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