I can only imagine that to be the case if the disc was not lying flat on the turntable for some reason. That laser part number is not familiar to me. I'll see if I can find some service info on this player, and see if I can think of anything else that you could reasonably try. It's reaching the point where you have to be starting to think that it's something obscure rather than common. An experienced eye might just look at it, and see immediately what the trouble is. On the other hand, sometimes faults like this can baffle even the most experienced of us.
Usually needs focus lock to start spinning the disc.
It resets to the inner stop.
The entire pickup moves to do tracking.
As others have noted, with this dramatic a change, it isn't likely to be a matter of an adjustment, or a bad cable. The servos are no longer capable of maintaining either focus or tracking lock. These are the sort of problems where without a service manual, it's unlikely to be repairable. A new pickup might help, but could also be an electronics problem.
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The entire pickup moves only when the tracking error reaches a certain point, at which time the pickup is bumped a bit, and the tracking coils re-center. Unless we're talking about an old Philips pivoting pickup with no tracking coils...
I agree it may be obscure and possibly an electronic problem. There are some differences in the part of the circuit used for the focus seach, so your hypothesis is at least possible.
What I have done in the past to examine what's happening when it tries to focus is to cut down a normal CD to just larger than the inner track. One of those mini-CDs might also work. If you see the lens not moving up and down very far, then initial focus search may be the problme.
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Right, it was in direct reponse to the original question but perhaps the reply didn't quite make it intact. :-)
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Hmmm, I've got a PS2 with a lens that has bubbles and scratches in it. I was thinking about trying a lens from a compact stereo CD unit I just shredded for parts. I realize its CD vs DVD but the lens's look the same. As observed "got nothing further to lose !"
it was "broken" when I got it. The scratches I can see from somebody previously getting in there and fooling around. Which they did. But the bubbles they've got me stumped. If I manage to get a picture of the lens I'll post it.
I've seen bubbled lenses from owners trying cleaning fluids, and also from focus or tracking drive faults, which have heated up the focus or tracking motor coils, resulting in a melted lens. It's worth trying a lens from a different laser ( assuming that there are no drive issues that have melted or seized the lens suspension ). I have never cross-swapped between DVD and CD lenses, but in principle, I don't see why there should be any fundamental difference. For any chance of success though, note carefully what I said about making sure that every last trace of glue is removed from the lens mount, and the replacement lens lip, before fitting it. It is essential that the lens is //absolutely flat// in the mount.
Long ago, I cut a large chunk out of an old CD with a hacksaw. That allowed me to position the hole such that disc was over the lens, but the lens could be seen through the hole. i don't know where that disc is now - buried somewhere deep in the workshop no doubt. These days, I tend to just lift the deck out, and just watch the lens action by looking under the disc or, if you can remove the disc clamp to get good access to the top of the laser, you can just hold a disc over the top of it at about turntable height, and as parallel to the deck as you can manage. You can usually get the focus servo to lock, and even 'play' with it by moving the disc up and down. It's quite fascinating to watch the lens follow the disc as though it was stuck there with invisible glue. I also have a circular magnet removed from a scrap deck's disc clamp. this is very useful for sticking a disc down to the turntable, after removing a disc clamp for eyeball access. You can also BluTack a disc down at a pinch.
Having had a further think about this problem, could it be that something is restricting the movement of the sled when the deck is flat ? Most players will shuffle the laser off the home switch and back on again, just to make sure that the laser is home, before turning on the laser and starting the 'disc in' initialisation procedure, ending in reading the TOC. If that shuffle couldn't take place, or was being restricted in some way, then the system control micro may not be getting the right switch signals to start it off. If you can get the deck out in your hand whilst keeping it connected, or otherwise get good visual access to it, try just opening and closing the drawer, with no disc loaded, and watch exactly what happens - laser shuffle, laser burning, focus seek etc, then try the same again with the deck tipped, and see if you can see any difference in what happens. If not, try the same with a disc loaded.
I've tried so many things, I probably looked at that. There is no restraint on the sled. It moves freely. The drive belts for the table are weak, but I twisted them and it seemed to work ok. I made sure it was fully seated when closed. It wouldn't clamp the CD if it wasn't. I have watched it seeking track 0 but I don't remember if that was only when tipped or if it did it when it was flat also. I believe there was no action whatever when it is flat, but I will look again. I can't see the lens assy from the bottom, but I will try a small CD and see if I can view it then.
Well, if the tray drive belt is weak, then the very first thing I would do is to replace it. I wouldn't for one second believe with absolute certainty, that the loading cycle is completing correctly and fully, just because the disc appears to clamp. I have had similar situations many times, where the final push of the mech, beyond just clamping the disc, works a "load complete" switch, and that extra little bit of mechanical resistance from the switch's spring loading, is just enough to hold it open. If, as you suspect that you observed, the deck does absolutely nothing when it is flat, then this would be a good indicator that the system control micro is waiting for something like a "load complete" signal. In this situation, gravity may well take over to assist the last little movement, when the deck is tipped. This would also make sense with your assertion that once the deck has read the TOC 'on the tip' as it were, it will then play in any position. The system control micro only needs to be told that loading is complete, once. Just change the belt, before going any further ...
NO, I have pushed it to be sure it is all the way in. The tip is from side to side so gravity is not at work here. A front to back tip will not cause it to operate.
Also, it will only CONTINUE to play in any position once play is started. If I tip it to read the TOC then lay it flat it will not start playing.
I HAVE discovered something else. The sled rides on 2 rails. one side has a sleeve on it, the other rests on a roller. It will move up about 1/16 inch on that side. If I try to start it while flat AND holding that side up it works. Once started, I have to let it go so the sled can move and it continues to work. Since that is not giving me a 45° tip, it does point to the lens or something inside being too far off to see the reflection in its normal position. Since it comes back at a 45° tip I have to think something inside is loose rather than the lens gimble as that only seems to move in the plane of the CD. HOWEVER, there isn't anything else in the assy that moves except the lens is there?????????? THEREFORE, it has to be the lens gimble, RIGHT?????????
yes point well taken. When I get both lens's out I'll check them carefully. If they do show a remarkable difference I probably have a dead DVD mechanism in my parts/junk pile that I can get a lens from. will advise...
Weeeeeelllllll ... Not necessarily. Firstly, just because you have manually pushed the tray all the way in, that still doesn't say that the whole loading process has completed correctly. There is often continued movement to complete the loading cycle, after the tray is fully home. Sometimes, for instance, a tray lock slides into place, finally working a switch, to tell the micro that loading really is complete. However, leaving that aside for a moment, I think that you can be pretty sure that a 1/16th inch of vertical play at one of the slides, is not correct. Are you absolutely sure that something is not broken or displaced or missing from the mech at that point ? It's not uncommon for there to be a phosphor bronze finger attached to the laser assembly, and resting under the slide rod, to take out just the sort of play that you are describing. If it definitely works under all circumstances with the deck flat, but that side of the laser lifted, then logically, that must be where your problem lies, right ?
Well, Tipping the deck doesn't move the the sled thru any part of that
1/16 inch, unless it is tipped past 90°. So something else on the sled is moving when it is tipped to cause it to see a reflection. The closed drawer position, I am sure, is not the issue. The sled doesn't move to track zero until it sees a reflection. I can hold it there in a position that otherwise doesn't work (flat or tipped front to back) and it still doesn't start up. The side that is loose appears to be designed that way. There is nothing that would hold it top AND bottom. Gravity keep the top roller in contact with the rail. A piece as you describe would assist gravity to hold it in just this position. There is no adj on that roller to make it bring the sled up. There were no loose pieces in the unit.
I might be able to jury-rig this to make the roller bigger and bring the sled up.
OK. I think that we have now reached the point where we have exhausted all the normal possibilities that any of us would be able to think of with this, which only leaves something very obscure and particular to your player. Having tried just about everything else, I can see nothing else it can be bar an internal defect in the laser. If taking out the play on the slide really does provide a cure, and you're not up for the cost of replacing the laser, which still just *may* not be the cause of the problem, then as it's just for yourself, and not a commercial repair, now might be the time to go for the 'technical bodge' option, as you suggest.
If the slide rod os easily removable, how about encasing it in a piece of thin heatshrink tubing ? This would increase the effective diameter of the rod by about the right amount, and give the roller a long life and durable surface surface to run on.
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