Wednesday, November 30, 2016

DVL-909 Repair Notes

The unit was purchased on Ebay for about $10.  The seller basically said he pulled it out of storage and it just didn't work.  Images in the listing showed both the LD and DVD trays ejected.


When it arrived, as per usual, the packing job was not adequate to protect the unit from damage.

The machine powered up but the tray would not eject.

Disassembled the unit and found the tray was jammed by the yellow switch lever that switches the eject mode from LD to DVD.  It had evidently received a shock hard enough to push it up into the workings of the tray itself.  Carefully prying it loose allowed the tray to be manually ejected by finger-turning the pulley just under the left side of the tray at the front of the unit.

The next issue I noticed was that the pickup had received a shock hard enough to move the left side up above its track so that the entire LD pickup was sitting at about a 30 degree angle.  Miraculously the motor holder was not damaged at all.  I removed the LD tray, then  removed the bottom rail screw to loosen the rail and free the LD pickup, replaced the pickup onto its track correctly then re-fastened the rail screw.

After replacing the parts and restoring power, the player was able to properly eject both trays with button presses, and the pickup moved freely along the track.  The player also correctly switched between the LD and DVD pickups.

The next issue - and probably the one noticed by the seller, was that the spindle motor was not engaging.  A simple continuity test of the pickup motor's socket (green and white wire going to the power supply) revealed that the motor was not making contact internally.

To remove the spindle motor, it was necessary to disassemble the top of the player and remove the entire pickup assembly.  The procedure was to remove the ribbon cables and sockets from the board to the right of the H-bar, remove the H-bar, remove the narrower of the two ribbon cables toward the front of the player (the wider one simply routes under the pickup assembly to the power supply - not necessary to remove it), the spindle motor socket, and the two ribbon cables toward the back of the assembly.  The "box" toward the rear of the assembly was removed, and the springs holding the assembly up were unfastened from their holders.  The pickup assembly is held in by six screws - these screws are slightly longer than the other screws and should be kept separate. The two screws toward the front are recessed very deeply and require a longer philips head screwdriver than typical to remove.

Once the assembly was removed I removed the three screws securing the spindle motor, removed the power wires from the routing clips and very carefully worked the spindle motor out of the assembly.

Once removed, I used a metal cutting wheel and dremel to cut a slot in the motor, and grind down the tension clips holding the bottom of the motor in place.  Once pried open I noted that the motor brushes were completely corroded.  After a vain attempt to repair the brushes with solder, the motor only worked for a short time before failing again.  Round about that point I noticed that Pioneer evidently used the same spindle motor in quite a few different models of LD player.  I was able to take the spindle motor from a different player with an electrical failure (a CLD-D605) and install it in the DVL-909.

With the replacement spindle motor installed and the player re-assembled, it was able to play Laserdiscs again.  Inserting a DVD caused the unit to switch to the DVD pickup, however the pickup was not functioning correctly, so it would simply report "NO DISC".  LD playback seemed normal except for side B playback where it would "skip" during the first couple minutes of playback.  Fast forwarding past the first couple of minutes resulted in normal playback for the rest of the disc.

My research into the skipping problem led me down several false paths.  I checked the upper gear track for debris and cleaned it with a toothbrush.  I cleaned and re-greased the upper rails and track.  When none of these things helped, it was suggested the M-holder (the plastic piece that holds the motor and the plastic gears that move the pickup) was damaged.  This seemed plausible because the pickup had been forced out of alignment violently during shipment - although I could see nothing wrong with it, it was possible it was cracked somehow.  I found a place called "Donberg" in Ireland that still stocked the M-Holder and the gears that go with it, and ordered replacements.

When the new parts arrived, I removed the LD pickup, thoroughly cleaned it, including removing the ribbon cable and cleaning it with Deoxit.  After installing the new M-holder and gears, the skipping during the first couple minutes of side-B persisted.  I removed the plastic upper rail and thoroughly cleaned it.  I readjusted the centering screw on the upper part of the pickup, but still the issue persisted.  The plastic rail is attached with clips and it hangs about half a millimeter from the top of the pickup assembly when installed.  Manipulating this by pulling the plastic gear guide up during playback seemed to allow the player to get past the skipping, but propping it up with twist ties did not allow it to play normally.

Eventually I discovered the problem was the little lever that acts as a brake and triggers the limit switch on the upper pickup assembly.  The brake was wedging itself against the pickup creating just enough tension to prevent it from moving normally during playback.  After trying to lubricate it with no success, I carefully removed the lever and examined the end which makes contact with the pickup.  There was a clear scuff mark where it had been wedging against the pickup.  I very carefully filed it down - barely enough to level off the top, then used a dremel polishing wheel and some polishing compound to smooth it completely.

This is looking up at the upper track.  The brake lever, circled in red, moves forward (to the right as this image is oriented) when the pickup reaches the limit of travel. The brake is supposed to both stop the pickup from moving and depress the limit switch. In this case the surface of the brake that came into contact with the pickup was sticking, preventing the pickup from moving back (to the left as this image is oriented) smoothly and causing the image to video to "skip" back randomly during the first couple of minutes of side B playback.

After re-assembly the system developed a new fault - the LD pickup became stuck in the rotator at the rear of the pickup assembly.  It would bounce back and forth furiously for a few seconds and give up.  I disassembled the upper part of the unit to get room to work then manually turned the worm gear on the pickup motor to get it back onto the track.  It gave quite a bit of resistance like some debris had become stuck in the gear track.  Although I never did see anything, I cleaned the section where it had become stuck thoroughly with a toothbrush and that seemed to clear the problem up.

Once the LD pickup stopped getting stuck in the rotator, I was able to confirm that the side-B skipping problem had also been resolved.

I noticed that the DVD pickup moved somewhat erratically and would occasionally get stuck when positioned all the way forward.  Getting the pickup out was a little tricky because the player does not like to eject the LD tray while the DVD pickup is on the bottom.  Getting it out required that I place a DVD in the player and wait for it to move the DVD pickup forward, remove the power cord, remove the crossbar and spindle clamp, then remove the DVD by hand, plug the player back in, then press the LD eject button and quickly remove power before the pickup makes it all the way back into the rotator, then manually eject the tray. This could probably have been done more easily via the service menu, but I did not have a means of using the menu at that point.

I removed the DVD pickup, then removed and cleaned its M-Holder and gears.  Next I used Deoxit to clean the ribbon cable and socket.  I used a q-tip with alcohol to clean the disc sensors and gently swab the dust off of the lens.  Once re-assembled the DVD playback functioned normally.

Unfortunately the front panel of the player offers no way of pressing "Enter" on a DVD, and the player came without a remote control.  Fortunately, however, Pioneer likes to re-use remote codes, and I was able to use the remote from my DV-525 DVD player to not only interact with DVD menus, but also access the on-screen player settings.

2 comments:

Pat said...

This post was really insightful! I recently bought a DVL-909 and it exhibits some of the same issues as your player. The unit powers on and the tray opens successfully, but I cannot get an LD or DVD to spin up. When I have a DVD loaded and press Play, I hear a grinding noise for a bit, but then it pops the disc out. For a laserdisc, as soon as I hit play, it tries to read the disc, but then just says open and pops the LD out a few seconds later.
Any ideas?

samson7point1 said...

Sorry, I didn't see this comment earlier.

My advice is to take the cover off the player and try to visually observe what it's doing. It's kind of hard to diagnose based on nothing but a noise.

- When the disc tray closes, does the spindle raise up and lift the disc off the tray and make solid contact with the clamp (the circular plastic thing in the middle of the cross bar)? If it doesn't raise all the way up and lock, it's possible you just need to replace the belt for the loader mechanism - they tend to harden and get smooth spots which make them slip. When the tray closes, that same drive belt has to push a bit harder to raise the spindle assembly and clamp the disc - sometimes they just can seal the deal so after trying and failing the operation will time out and it will eject the disc.

- If the disc is being clamped, does it spin at all (does any disc spin at all?). If not then it's possible the spindle motor is shot. With the disc ejected, try turning the spindle by hand. That should give you some idea of whether the motor has seized. If the motor has seized then you might be able to revive it by lubing it with some silicone lube and hand turning it, but chances are you'll have to replace it. If the motor turns freely but won't spin when there's a disc in the drive, you'll have to figure out if the problem is with the motor or somewhere else. For that you're going to have to find the spindle motor wires (I honestly don't remember where they are, but there should be two wires coming up from the underside going to a connector on the main board. Once you identify the connector, unplug it and use a continuity tester between the two leads - if you don't get any continuity then the spindle motor will need to be replaced. If you do get continuity, the next thing you'll want to do is to attach multi-meter leads to the socket on the main board and see if the player tries to apply voltage to the spindle motor when you insert a disc. If it does try to apply voltage, then try replacing the spindle motor.

If the disc is fully clamped and tries to spin, then the next thing to check would be the pickups. The player works by trying to read a disc with whatever pickup is out at the time - if it fails, it will switch to the other pickup and try reading the disc again. The simplest solution is to try cleaning the lenses on both pickups. Use some isopropyl (91% is best) and a q-tip (damp, not dripping) to gently wipe the lens. IIRC there's also a light sensor on one of the pickups that should be cleaned. If the lenses appear clean then the next step is going to be kind of annoying, but you're going to want to very very carefully remove, clean and re-seat the ribbon cables for each of the pickups. I recommend deoxit - just be careful not to get it on the lens.

Let me know if any of that helps.