Great video! As always, something that seems simple turns out to be a real pain in the neck. I think the correct sequence for DVD reading is that the mechanism grabs the disc first, then the laser checks what type of disc has been inserted, activating the laser lens movements.
The lens assembly has to be fully UP before it will attempt to read a disc. Take the tray out completely and manually move the big gear that drives it to the closed position so the switch is in the correct place. The same motor drives the tray and raises/lowers the lens assembly. When closing, help it to fully close. The first thing you need to do is replace the belt. Also find the datasheet for the chip that drives the motor while you're waiting for the new belt to arrive. See if there are any resistors that set the drive voltage/current to the tray motor and increase the voltage by 0.5 to 1V. That should help the motor to fully close the tray if the belt is slipping.
I once worked on an Aiwa unit which had a 3 disc carousel mechanism that was very similar to yours and was also quite a pain. In order for it to eject, it had to first optically detect (via the pegs underneath) that the disc carousel was parked in a way that the disc 1 tray was facing towards the rear, i.e. right under the laser assembly, and also it had to run through the sequence of attempting to read a disc (and either succeeding or failing, whether or not a disc is present), and only after going through those motions would it then be allowed to eject, otherwise it would stall on "DISC READ". Of course, in order to do so, the whole tray must first fully park closed to allow the sled assembly to clamp and activate the laser reading sequence. In my case, the problem was caused by a single peg under the carousel which had broken off, thus confusing the unit as to what position it was in, and so it never detected the disc position to be "centered" under the sled. It would simply start to spin, but then stall at a point partway between two disc trays under the laser, thus never completing the sequence and hanging on DISC READ. In other words, the carousel must first align itself by spinning and then braking at just the right moment before the sled/laser would activate, so that the unit knows for sure that it's lined up properly. So, to summarize, two conditions must be met before the laser activates: 1. entire tray must be fully parked to allow the switches to contact and the sled to clamp, and 2. correct carousel position detected, thus the carousel must be installed properly for the whole sequence to work. It might be worth looking at the belt which spins the carousel, as that could be another cause of the problem.
You checked the switches and continuity to the plug but do check for dry joints around the plug as well. It may be that it's still not detecting that it's in and dry joints would explain why it sometimes does things and sometimes doesn't. I'd also take the whole mechanism apart and see what's getting stuck - seems like either a spring flew off or something broke (which might not be pushing the switches in correctly/at all?).
Hi Colin. The disc "clamp" must come down first in order for the lens to attempt a focus ( up/down) motion. If it sees a disc then the spindle starts to spin. So check the mechanism that moves this clamp down.
The fact that it sometimes says "open" even after it pulls the tray in all the way (is the motor continuing to be powered?) suggests it doesn't know that the tray has closed completely, and I suspect this is part of the problem. As others have suggested, this could be a broken connection, and seeing the switches being in a weird state will likely confuse the controller. The tray hanging up as it's going in is another sign - a broken part (the piece that actuates the switches?) could be causing that.
I would expect the laser sled to raise and clamp the disc as the tray fully shuts, before the laser starts to focus. I am not familiar with this particular product but I would some expect some mechanical interaction between the tray and sled.
I would concentrate on the mechanics first: 1. fix the disc tray so it's moving freely in and out. 2. fix the "laser- unit- elevator" part - maybe it's driven from the disk tray- motor as well. If this is the case, a new (and proper) belt will do the trick I think if No. 1 and 2 are working as designed, only than the laser will turn on and the lens will moving in order to focus. Might be a security feature, that the laser will turn on only when certain conditions are met. Good luck and remember: "Don't look into laser with remaining eye" ;-)
There's a tiny possibility that the assembly is not rising because of the slipping belt. Belts of various sizes in that region, are on order. The crashing disc tray, I don't know why that's happening, but can investigate once the belts arrive.
I got a JVC mini stereo/CD that's stuck on "Disc read" until i forcibly move the little gear on the bottom left of the cd tray with a screwdriver. Then it reads perfect. Yet i have checked everything 1 year ago, the belt was fine and pretty sure i greased everything (laser tracks etc..), Maybe some extra Gunk or i don't know (cracked gear ? pretty sure there wasn't none)
I got a LG HDD&DVD recorder around the same time. It was an awful experience all over. Starting with the unresponsive UI over the wonky DVD writer to the propietary file system on the harddrive. Replacement machine had the same troubles. Got myself a Panasonic which was way better(also more expensive). Today I have a stack of Panasonic UHD BD players as a means to keep my movie collection alive and growing. I have started experimenting with copying my BDs to SSD, because the day of BDs demise is nearing fast.
I went down much the same route except these days I rip my BD and 4K discs to a dedicated Zidoo 4K media player and that's my main way of watching movies.
First DVD/HDD recorder I bought was an LG machine, it was pretty rubbish to be honest. Very slow and clunky to respond with just an analogue tuner, so it was replaced a year or two later with a Sony model which was 100 times better in every way for recording from Freeview. The LG was never really used to play DVDs though as I had at the time a high end Pioneer DVD player specifically for that, but the Sony that replaced it did end up becoming my main DVD player.
