Hi all! I picked up a CLD-2070 at a yard sale. It powers up, then shuts off 4-5 seconds later, no matter what it's in the middle of doing. The first problem I noticed was the loader was entirely stuck with dead grease, so gave it a good greasing hoping that was all that was wrong, but no change, other than that it will now load and eject discs 4-5 seconds at a time.

Observations:
It powers off in the same time no matter what it's doing and what motors it is attempting or not attempting to run, including sitting there with the tray full open, tray closed with disc, tray closed with no disc, and in the middle of loading.
If I hold _power low, the power supply will stay on, but all movement halts - the controller is intentionally killing it. If I hit the power switch again, it acts exactly like it does if I don't hold _power low.
It seems to recognize discs quickly, but ejects them. If I shut the tray with no disc, it'll keep trying to focus and seek for the 4-5 seconds before it powers off, but if there's a disc in it, it seems to lock focus within a second or two, wait a second or two, and then eject the disc, getting about a second of ejection time in before powering off. At no point does the spindle rotate. I have not observed any rotation from the spindle in any of my testing.
All power supply rails I could easily find to poke at seem good. I have +/-15V, +/-5V, and always on 5V to the control panel. There may be others less-easy to poke at?
Tilt, height, seek all seem healthy.
Unplugging the spindle speed sensor doesn't change anything.

I haven't been able to find a service manual for a CLD-2070. The one for a CLD-91 seems the most similar of the ones I could find.

Is there anything common or simple I should check? My assumption is the controller is getting pissed off about something, but I don't know what. Should the spindle rotate before it ejects the disc after focusing? Only reason I'm not jumping on a spindle problem is that it does the exact same thing even in situations where it wouldn't be trying to run the spindle. I couldn't find any reports of the same symptom searching. I found a couple people with bad wires to the front panel causing poweroffs, but that's not the case here. Does anyone know under what conditions the controller will decide to power off the unit even when it's in the middle of something else? A watchdog timer? No communication on some bus? etc...

At this point I'm about ready to toss it on ebay with a big parts/repair warning, but figure I should at least ask in case I'm just being stupid and missing something obvious...

Thanks!

The CLD-2070 and CLD-3070 (essentially the same chassis) are very notorious for the dried grease issue that will cause a frozen mechanism which includes your current shutdown issue.

In order to fix this, you literally have to take the entire mechanism apart completely to get all that old rock hard grease removed. It is definitely not an easy job to do since this is a 1st gen auto reverse unit that is overly built (I've done it once before and I needed help to get it back together because I had issues getting the gears aligned properly for proper timing).

The CLD-91 service manual has detailed drawings of the mechanism that will help if you decide to proceed with it (the current 3070 manual we have on file doesn't show very much for some odd reason).

I haven't spotted any problems with the mechanism, in that every function it seems to perform moves freely. Slider, tilt, and height all are smooth and fast. To double-check tilt, since you can't see its gears from on top, I just popped out the carriage, flipped it over, and tested the tilt motor directly - a single AA battery is plenty of power to quickly spin it from one end of its travel to the other. No grease issues on the mechanism.

Some more observations:
If I spin the disc by hand, it does not try to eject it, but still powers off after 4-5 seconds. If I don't spin it, it ejects it. I don't know if this is because it can't focus while I'm bouncing it around, or whether it's happy it's spinning.
I tried powering the spindle motor with a 9V battery, and it barely moved, needing to be started by hand and then barely staying running. I then got out an adjustable 3A power supply, and it maxxed out the supply at only 1V.... And then suddenly took off a few seconds later. Now it runs great off a 9V battery. So it had a spindle motor problem. It sounds absolutely terrible at speed, but that's not the current problem.
It still does not try running the spindle.
If I unplug the data connector between the front panel and the control board, the unit stays on instead of powering off, confirming the control board is instructing the front panel board to kill the power. Of course, it doesn't function with this connector unplugged.

So, with a confirmed spindle motor problem, I've been poking more at that part of the unit... the schematic in the CLD-91 manual very much does not match the spindle description in the (incomplete) CLD-3070 manual, but looks closer to the boards... The schematic in the CLD-1070 manual has similar labeled signals to the description in the CLD-3070, but doesn't match the labels on the connectors... And I don't think any of them match my machine. I really wish I had a service manual for the CLD-2070. But it seems that this wouldn't cause the unit to shut down, as it doesn't try to run the spindle when, say, in the middle of ejecting the tray, yet it still powers down while doing so. Also, I don't see any way the controller would detect a failure in the spindle drive circuitry. So I probably have multiple problems.

I wish I had more documentation in general... Everything points to the controller deciding to hard power off the unit in the middle of doing other things. And none of the manuals mention that as the response to anything.

This is probably going to be someone's parts unit...

Where are you located? May not be worth it for shipping.
Thx

First thing to do is put a voltage meter on the power supply output voltages and see if the proper levels are reached. The unit could be powering down due to a power short. If you find a bad power pin then use have to start isolation, this can be a lot of work. You should have +5V, -5V, +13V, and -13V pins.

Already checked every power supply output I could find. All were perfect. Well, I didn't check the -23V and AC to the VFD, but the display is nice and bright...

I just 'scoped the power supply rails. All good. The unregulated +/-15 rails have the expected small amount of ripple, while the -5 and the various +5 rails are all perfectly solid.

I tried unplugging both of the processing boards, with absolutely no change in behavior.

Are you sure the clamper is really locking on to a disc firmly? I know this is a common issue that will definitely prevent the spindle motor from engaging. Usually it's a slipping belt causing it but I don't think a 2070 with its tooth belts would have this affect.

The powering off happens in the same 4-5 seconds even if it's not doing something where it would expect a disc, like in the middle of loading or ejecting the tray.

Well, I found another problem, but fixing it didn't change a thing. I decided to visually inspect the only board I hadn't looked at yet, the part of the FTSB that's under the mechanism. Found someone had put too long of a screw in the little access cover on the bottom, and shorted part of the "FTS SCAN" circuit to ground. It's the node with C21, R69, and R71 on the CLD-91 FTSB schematic. But, this is driven through a resistor and capacitor from the microprocessor, so it probably didn't burn out the output pin, and it looks like grounding it would cause tracking problems, not long-term damage, so I don't think it's likely to be the cause of the powering off issue... Or would it? How sensitive are these microprocessors to unusual loads on pins?

I'm about ready to put it back together and give up. I've been poking random things with my 'scope, and they look like random things doing random things, and without a lot better documentation that's about all I can tell...

Progress. The unit seems to be shutting down due to the "FTS EMERG" signal from the FTSB. If I disable this signal, it'll spin up and try playing a disc, complete with the nifty flop to side B when I hit the button on the front panel, but it doesn't seem to actually be playing it. The disc I'm using for testing is so badly warped that it hits the head while spinning up, so this may be part of it, or it's due to the underlying issue that's causing the FTS EMERG signal. Looks like this signal is designed to detect a DC offset on the focus and tracking drives, but the lens appears to be moving in the expected fashion. Will dig into this when I have more time later.

Closer observation of the lens doesn't show any tracking movement. When playing, the display quickly switches between two track numbers, as suggestive of a complete lack of tracking. May have a shorted tracking driver and a burnt out tracking coil to go with it. Will do more testing later.

Tracking servo is putting out +14.2V constantly. Nothing on tracking return. Measured tracking coil at the flex cable connector on top of the side-b-flippy-thing, open. Have bad flex cable or bad tracking coil, in addition to a possible or likely driver fault. EDIT: Still measures open at the little cable going into the laser assembly. EDIT #2: The tracking coil itself, measured at the connections at the lens, not the ultra-fragile-looking wires to it, still measures open. Looks like this unit needs a part it's not going to get.

Well, seems I'm taking this repair further than I probably should...

Looks like the tracking coil leads are cracked somewhere under the glue where they connect to one of the lugs. I do not have continuity between the two red arrows, from where I scraped some of the glue off the two twisted magnet wires, to the lug they're soldered to. I do have continuity between the magnet wires and the lug at the other end of the coil, about 9 ohms. So I just need to solder a little jumper from the magnet wires straight to the lug... Except that, you know, it's so tiny I can barely see it with my naked eye, barely can even get a meter probe to it to measure, and soldering it will be a total nightmare... see the pic with a meter probe for scale. Fun.

Wait, this is the tracking coil on the laser???
Sorry you can't fix that.

Also if this is for something else, sorry you can't fix that, its just too small and you need to replace that part.

Can't?

I'm not happy with my repair. I slipped with the iron and got a blob of solder on the outside of one of the tracking coils, probably shorted a couple windings. Really, really pisses me off that I did that. And, in the process of trying to solder on a patch wire, I ended up just making the new joint with solder blob, no new wire. But....

And it even plays side B, too! I'm currently listening to Close Encounters of the 3rd Kind. I don't actually have a TV to connect it to to see how the video looks. (I mostly work on audio stuff; not a movie person)

And, just to make it clear for anyone searching, the coil repair fixed the powering-off-after-4-seconds issue. Here's a brief overview of how this is, from my understanding of it:

The FTS EMERG (focus and tracking servo emergency?) signal from the FTSB is two resistors connected to the focus drive and tracking drive signals, that then goes to the power supply board. The power supply board adds more resistors from the two switched +5V supplies and the -5V supply, to also allow it to detect power supply failures. If the servo outputs are zero, and all the power supply rails are good, this averages out to 0V. The power supply board then has a couple transistors to detect if this signal is significantly far from 0V, with a resistor and a capacitor to provide some filtering. If this signal goes away from 0V and stays there long enough, the power supply board pulls _EMERG to the control board low. And, approximately four seconds after this signal is pulled low, the control board shuts the unit down and tells the front panel to kill power to the unit.

If either the focus or tracking coils are open, the servo feedback loops try driving them to full power, due to lack of anything making it back through the respective return line and to the respective current sense resistor. These high voltages (15V rail minus one transistor drop) throw the FTS EMERG signal enough off zero to trip the threshold on the power supply board, set _EMERG, and cause the unit to power off. A shorted driver or other feedback loop problem could also cause full output, and if the coils were good, they'd be nice and crispy within seconds at full power - hence why cutting the power to the unit is the response to any continuous large signal from the servo drivers.

So, for anyone who finds this thread looking for why a unit shuts off, check the focus and tracking servos... would have saved me a lot of troubleshooting if I'd been able to find this information when I started! I was looking for power supply and other such issues.

Now to put some glue over the repair, and put the rest of the unit back together. Also should find a TV to test video output. I don't know how long this repair will last, but at least I've confirmed the FTSB and FTSD are good, and if it fails again, it just needs a replacement focus/tracking lens assembly. I'll be sure to advise the new owner of this unit's repair history, as this definitely isn't a repair I'd give any warranty on.

Well if I know what part then yes you can't.
I'm thinking of the laser coils, that's the only part I've ever heard of with coil but the again I'm not a tech.

Glad you got it working, hope you enjoy laserdisc.

Yes, it was the laser coils. Specifically, the tracking coils that keep the laser centered on the track.

Wow I was told by many techs in the past you couldn't fix those,
once they were broken or burnt from poor adjustments they were gone and not able to fix.
Glad to hear it since there are no lasers or parts for replacements.

I was lucky it was broken right at the lug. That said, my fix isn't very good. It may not last, and I caused collateral damage in the process. A replacement lens assembly would be the correct repair.

I searched extensively for what would cause the unit to shut down 4-5 seconds after turning it on, and didn't find even a single mention of a problem with the lens assembly being a cause. Hopefully my troubleshooting adventure helps someone else...