Pioneer CLD-2090 or RCA LDR-600 schematic/service manual

[Mickey_Moose]

Gentlemen - I am looking for a service manual (or even just the schematic for a Pioneer CLD-2090/RCA LDR-600 laser disc player.

I am having an issue with the power on sequence (or lack there of).

They are pretty much the same unit.

Basically the unit will power on and nothing more, normally the laser head assembly does a move out and back to home procedure which is no longer happening.

Many thanks...for any help you can provide.

[vtech]

Use to work on many LD's way back. Assuming that you are at least somewhat familiar with the standard operation, sounds like you may have lost the "drive" voltage which could be anything from a mechanical switch or possibly a regulator?
Not sure if you can find a free manual?
One thing you can;--- without taking anything apart in the load mechanism---try to move the mechanism or better yet see if you can move the tray by means of turning belt/pulley/etc and then power up the unit and see if there is any activity? (it should attempt to reset itself and the laser movement would follow afterwards).
If I remember correctly, on some of the power supplies there were voltage markings that could be used as a guide?

[Mickey_Moose]

Thanks for the reply.

I did try manually moving the tray and such out of position and nothing seems to work.

Power supply voltages seem normal based on the markings on the PCB that there are.

What normally happens, power on, laser assembly moves out of home a short distance and back. This does not happen. I reseated the ribbon cables and checked that the assembly is free to move and not binding. I also checked the home position switch and is seems to be changing state. The mode selection switches also seem to be ok. I also thought that maybe an issue with a switch that would be activated when the transport lock screw is in place, but that also checks ok. Note: these switches where just checked via the ohm meter vs voltage change while on (which is really hard to get at these switches with the unit together).

Now it could be the motor on the laser assembly is either bad or not getting it's drive signal, which is why I was hoping for a schematic. The motor is not assessable when together - I would have to trace the signal back through 2 of those "plastic" ribbon cables to where I can measure it. Something I was too lazy to do at that point, but may have to do in the 'next round'.

[Mickey_Moose]

Just to add - I think the tray and such will not move until the head position is verified to prevent damage.

I did not try powering the unit up and manually moving the head out and back and see if the rest of the unit 'works' (tray out, etc). I just thought of that now - something I could try at the next sitting as well.

[vtech]

Sounds like you have done a good bit of checking.
As far as causing damage, you do not have to be overly concerned as long as there is not too much movement of the mechanism.
Another way to attack this is to look for driver circuit(ie motor/mechanism driver IC). Almost always there is some sort of a driver present with or w/out some sort of a heath sink configuration. You could look up the datasheets of the ic and look for needed voltages. On many occasions I have been able to utilize that when there is no schematic. The LA or BA series driver IC's were common among many of the pioneers.
You mentioned ribbons; the white/blue aluminum ribbon connectors were known to be problematic specifically at any of the bend points.

[Mickey_Moose]

Ok, so what I found:

Ribbon cables are good.

LA6510 is the driver for both the head motor and the mode select motor (if that is what they are calling them).

Both of these motors are working - bench tested.

I am getting voltage across the head motor (although it is only 4v - seems low).

No drive output (pin 2) from the LA6510 for the mode select motor - no input either.

1 side of the mode select motor drive input (pin 3 of the LA6510) traces back to the main processor. The other side, pin 4 goes off into never never land. My understanding is that either of these pins should go 'high' to drive the motor in it's appropriate direction. That does not seem to happen, but is it a fault of the processor so some switch someplace that does not seem to be working? I did check the switches that can be seen - not sure if there is any 'hidden' ones in the mode select assembly (there are a couple on top - 1 is tray out, and the other 2 escape me at the moment of there function - I think 1 was tray in and down).

Now I can't seem to find a data sheet for the processor, PD0081E, so no idea how it is working.

Power supply seems to be working, getting +5v, -5v, +14v and -14v output.

I suppose I can now blindly replace the LA6510 and/or processor and see what happens - the problem will be at finding them. The LA6510 seems to be listed on eBay, but can only find the processor via Alibaba - which brings up the question if the chips are legit or counterfeit (I know some people have been burned).

Suggestion(s)?

[vtech]

Aha, I was not aware this is the unit that plays both sides;
At this point, I think you are better off trying to purchase a print rather than shot gunning by changing parts. As far as getting stuff from China, it is in fact a risk but that may be the only way?
Not sure if this helps but pay close attention to the video of a RCA unit as to the sequence of events from power On....
https://www.youtube.com/watch?v=7lE2ut1jBOo
If I remember correctly, the position of the spinning laser mechanism is the first in line and it must be at home before anything else would move.
What do you get on the front display as you turn the unit on? Any activity on the display? If you press any of the front panel buttons do you see any response?
Seriously doubt if you have a problem with processor. There are some CLDxx pioneer schematics posted on hifiengine.com that may be similar to your unit? Perhaps you could use it as a reference?
Also you mentioned 4v across the head motor which does not sound right. That may be the key? Is that a loaded down voltage reading?

[Mickey_Moose]

Power on, display comes on like in the video, nothing else. Pressing any of the buttons on the front panel does nothing. Manually ejecting the tray and then power on does nothing (comes up exactly as if the tray is loaded).