Hello everyone, just thought I'd share my 2 ongoing player projects I've acquired over the past year,
these were players I thought I could take on with a little tinkering and get running again,I tried my best to read up on the common issues and learned a lot from the site and others, but at this point I don't think I can do any more without some help.
First the 503:
This player could not clamp the disc well, when I got it, 1 out of 10 times maybe I could get it to load on it's own, a little better with a CD, Once loaded it played fine, changed sides no problem.

When I finally got the parts I replaced the grip ring as it had disintegrated and put on a new belt.
I did add some grease to some of the plastic gears, maybe this caused more issues I dont know.
after doing all this the player actually performed worse, with no disc and tray removed the Assembly goes up maybe halfway
and then the belt slips. I thoroughly cleaned the loading belt and its pulleys to ensure no grease or dirt was on them.
still same result.

the player does have a dent on the bottom of the chassis and I'm wondering if theres some alignment issues.
I've also read there could be a power supply issue causing loading motor to run in overdrive, not sure about this.

Now after pulling the player out to tinker with it I found a new problem, the player can no longer read an LD, it spins up
and spins down again and stops. I think this maybe the table of contents issue. I'm afraid maybe I shorted something when working on it.
I tried a cd and it does still play a cd fine, after you help it load.

Now for the 504

this one was probably a mistake, should have asked more questions before buying, but oh well.
It was listed for parts. I thought maybe it just needed an M-holder which it did and then some

I found the pickup laying loose on the bottom of the player, the pickup motor is completely gone and also one of the gears is missing. the metal rail on the bottom was broken off aswell. I think I found most of the parts fallen down in the bottom of the player, I do know I need at least the one gear and the motor ( and m holder of course)
I don't know if the pickup is even reparable, I thought maybe with a new motor could be soldered onto the pickup, but I
don't no if that's even possible since the traces are pretty well broken off , and I'm deterred by the fact the parts alone would
be way more then what I got the player for.

So I thought I'd ask for some more knowledgeable opinions/advice since I'm just fumbling around at this point.
It would be nice to get one of them going, I think the 503 certainly has a better chance of the two, but I just cant seem to get anywhere with it.
the 504 I've kind of written off as parts to be honest but maybe there is something to be done?
Any advice is appreciated.
Here is the 504 pickup

First of its great that you are trying to save these machines. Even though both are in bad shape right now I still think they can be brought back to life. Problem is parts availability is getting tough. For example the M-Holder is no longer offered for sale which is a huge bummer, sure its available on some sites but not at pioneers site anymore.

503

From reading your description after replacing the belts that should have been enough to lift the assembly up to make a proper clamp but that did not work.
We need to look at other things that could be preventing that. Did that dent in the bottom kink the main lift assembly so its now binding when it tries to lift up? Is the motor weak and can't get the assembly up? What happens if you remove the belt and then manually turn it? do you hit a point of resistance while its lifting up?
But the fact that it reads a cd when you help it load> do you mean help the assembly lift up? The other thing is make sure you clean the laser eye with a q tip and some windex just get a small amount on one end then dry it off with the other end. Don't push down at all just a light dab. Do not use alcohol to clean the lens. Its possible with all the messing around and fixing it got dirty.

504

This one may be more difficult like you said. Can you get a better picture of that laser assembly? I want to see the area where the motor ribbon was sheered off. Is part of the ribbon still on the motor? This can be fixed if you have enough of the trace left. What you do is lightly scrape off the orange covering until you get down to copper. That is when you can solder on a very small wire to rebuild the connection. Problem is you need that 2nd gear or you are dead in the water if you some how find that you are set once you get a new M-holder. I was able to rebuild an M-holder from pieces but all the pieces were there.

Is the 503 the same laser pickup as the 504?

Well I tried the 503 again, I found part of the problem is on the metal rail of the disc tray there is grease and when closing it seems to be flinging grease on to the belt. I'll try to get any more excess grease I can find. I did get it to load on its own a few times after cleaning the belt again but now it started getting stuck again and now the tray doesn't seem to want to open for some reason.
And yes what I mean by helping it load is lifting the assembly by hand. I can turn the gears and lift it manually and that seems to work ok.
I've been getting it to load and play a CD almost perfectly, however I cleaned the lens as you described and it made no difference with the LD, it spins up very fast for a few seconds then spins down again.
Sorry for the poorly lit photo, finally got a better one today, my camera doesn't focus in very close but hopefully this one has more detail
504 pickup:

I usually solder two wires from the slider motor and to the pads of the connector. Keep it short as possible. Just follow the two traces to the connector pads. Done this a lot when they were shipped hard or not shut down properly before shipping is usually the cause. The lens may be bent also do to floating around during transist.

Laser optics Con. PIN 1# = GROUND TO MOTOR -
PIN 2# = POSITIVE +

Thanks for the info I may try to attempt this. I will still need the motor vxx2082 and I think also the gear vnl1639, since getting the dvl-90 I might focus on that for the moment but try to work on all the players at some point.

Crap you are right the ribbon sheared straight clean off. That will be a little more difficult because the traces are so small in that area. But as grasshopper said can still be done with a steady hand.

You have a DVL-90 that's a good unit but don't give up on these they just need a few parts and work to make them whole again.