1982 Pioneer LD-1100 Laserdisc [PAL]

Player details can be found here: http://www.laserdiscarchive.co.uk/laserdisc_archive/pioneer/pioneer_ld-1100/pioneer_ld-1100.htm

The pioneer laserdisc player arrived at lunch time, very well boxed and padded so it survived the trip from Devon.

The player was outwardly very mucky and looked like it has been splashed with a lot of plaster, that pinky coloured mud. Thankfully this was only surface and the player cleaned up very well. Nothing had made it inside and all that was found were a few cobwebs and not too much dust.

Unlike all the Philips  I've encountered thus far from this period, the LD-1100 does not present "sticky belt syndrome" as it appears to use direct drive. The mains cable has been snipped which is expected as it came from a recycling centre. Next steps will be to do some preliminary checks on the PSU and protection fuses, then consideration as to the best approach to power up.

For now some photo's

Power applied and no dramatics or magic smoke escaping. I could hear the laser sled returning to the home position, once there I could now open the door interlock and raise the lid. Connected up to the TV and tuned the receiver to the Laserdisc player. Inserted a disc, closed lid and pressed play. Pressing play lit up the play indicator lamp on the front display there was a flash on screen and an audible thump thump from the player.

I overrode the interlock and with the disc removed pressed play, the thump thump is the Objective lens moving up and down. I can also see the laser beam is activated, both these are good signs. However the main fault seems to be no platter drive spin-up,  time to investigate why. Starting point will be to understand what the process of start up should be and the motor/servo drive circuit (SPDL motor) and why it is not spinning up. There is 19V at the motor and I note when powered up and down the motor does jiggle.

That looks like a very early 1st generation Laser Disc model, I take my hat off to you for delving into early micro-processor and servo electronics riddled with IC's and so forth! I'd be too scared to jump in the deep end with something like this! Hopefully you can get the motor/servo issue sorted. The cosmestics and the electronics/board layouts remind me of Pioneer audio from 1980's, especially their Linear Tracking turntables and so forth!

Posted by: crustytv

That's an NTSC version of Timecop isn't it, or am I missing something?

Correct, it is.

In case anyone is interested, this thread is paused whilst I await the LD1100 service manual to arrive from Germany and an official Pioneer trouble shooting fault guide from USA.

Although the V1000 service manual in the data library is allegedly the same. I decided if I'm to tackle this player then I should err on the side of caution and purchase the correct LD1100 service data. There may be subtle changes and I don't need blind alleys and discrepancies leading me astray.

The dealer fault guide is a total gem of a find, it will be essential and cost me an arm and a leg. It comes from a closing down TV shop in Arlington, TN that was a Pioneer dealer. I've seen some of the contents and its a very comprehensive manual, it covers both PAL and NTSC versions of the LD1100. Lots of stock faults and service guide steps with a similar flow chart style to fault finding that Thorn produced. I spotted the fault listed I have with the SPDL motor detailed, so fingers crossed when it arrives it will get me started on that fault and cover any other fur-balls the LD1100 coughs up. Both should be landing at the crusty caverns towards the end of the month.

Meanwhile I've also commissioned two custom built perspex fascias, one for the large rectangle display that shows the various player states and one for the smaller right-hand remote sensor display. Both were missing when I received the player, I know it might be money wasted should the player be a dud but I'm ever the optimist and this player will live again.

Hi Chris, I'm following this with great interest. If it's any help I've just downloaded the manual this evening but there's no circuit description to guide me as I've no experience with Laservision and not even seen one in the flesh. Only serviced a very few CD players but with the symptoms you have my first check would be the FOCS LOCK signal. In the library manual this is fed to Z6 pin 4 via plug N18-7 on the CONT board. As there is a bar over FOCS LOCK it's active low so if focus is achieved this should fall from 5V to below 1V, I would imagine if it follows CD player techniques when low only then will it attempt to spin up the disc. 

A surprise today as I was not expecting the service data to arrive until the end of the month. Both the manual from Germany and the one from the USA arrived together. 

A brief read of the LD1100 service manual clearly shows I was correct to get it as there is far more detailed and relevant info to the player before me, including a full circuit description. I will in due course scan and upload it, meanwhile I have made it clear the one in the library is for the V1000 NOT the LD1100 so disregard it if you've downloaded it.

The Fault finding guide as expected is equally superb with many detailed fault condition paths, methods of identifying and its associated resolution. Also a full set of oscillograms. 

Thus far £65 on data, £10 for the replacement fascias and the £90 for the player, so i'm full invested and committed (soem might argue I should be) to repairing this player. Hopefully armed with all this I now have the best chance of tackling the player, only limited now by my zero experience of laserdisc but that's never deterred me in the past.

Some swotting now and scanning to be done.

Whilst scanning the service manual I came to the Focus servo section and it states that when starting, the objective lens is first raised (focus on command from the cont board)  to a position where the focus servo can be applied and once it has been properly focused "in focus", the focus servo loop is closed and a "focus lock" command output is sent to the cont board. The focus servo is thus set to normal operating status, but if proper focussing cannot be achieved within 1 sec after application of the "focus on" command, this command signal will be stopped temporarily and the focussing operation retried 4 times. This is the light thumping sound I heard and the observation I made of the objective lens bopping up and down.  At which point if it still cannot lock the focus servo mechanism, the player is switched automatically to reject mode.  Also some worry info found about possible duff SPDL motor. Anyway no point jumping to conclusions, this is my start point and I need to check all the reference high and low voltages and the expected waveforms.

Service manual including schematics now in the data library

Anyone who has downloaded the recently scanned manual, is up for a shared headache and cares to pitch in, feel free, otherwise these comments of mine serve purely as a diary log for me to refer back to.

This is going to be fun! not used to all this "L" "H" malarkey..... Some serious learning curves lays ahead here.

Ok, with the above in mind this is just me thinking out loud.

I've established the fault appears to lie in the focussing servo being unable to lock, this is supposed to occur in the first second of play being depressed. Failure to do so means it drops into a sequence of 4 retries after that it rejects and stops, that's exactly what's happening.

I checked the voltage at TP1 and its 12V which I believe is correct. I also tried to scope the S-curve (focus error voltage) at TP-1 when play is pressed but as this appears in fraction of time (500us) I've not been able to suss how to catch it even with the timebase turned down.

Therefore I next checked the "Focus On" voltage at N7-5. Now according to the manual "Focus On" is "L" which I take it is "active Low" but what on earth does that mean with regards to an actual voltage, as far a I can see there's nothing listed which makes it a total mare!

I have 3.4V on N7-5 when the player is just powered on and 3.4V when the play button is pressed, so no actual change takes place and I suspect that's not correct. Besides that, its way too high as that would mean its putting 3.4V onto the base of Q3 which again I believe is only expecting to see 600mV. 

I'm focussing (excuse the pun) on these two anomalies at present. Once again I feel like the ape standing before the obelisk in 2001..... ? 

It sounds very similar to the later CD format in that respect, in that Fok (focus ok) needs to be achieved first.

I am much more familiar with CD/DVD players than these earlier format machines, having repaired many of the later machines and had virtually nothing to do with the earlier format.

Pioneer CD spindle motors were notorious for failing in their 1990s range of machines, one trick to determine if they were faulty was to temporarily disconnect the motor feed circuit (to prevent damage to the driver circuitry) and spin them backwards briefly with a battery* or PSU and then reconnect and re-try, if the machine now worked a new spindle motor was required, it was known the commutator/brush interface could go high resistance or partially leaky across the segments and/or have dead spots on these motors . 

*Although not recommended I often used a 9Volt PP3 to do this, you just needed to be fairly brief in the application ie. just enough to let the motor spin up flat out and no more ? so as not to burn the motor out , in fact I used to spin them both ways and squirt a bit of servisol switch through the holes in the motor end casing (brushes end plate). I did this on one of my own CD player machines (the owner declined the repair and told me to keep/scrap it)  so instead of buying the motor as it was now mine I just ran it to see how long the "spin trick" actually lasted, the answer surprisingly was at least a couple of years ? , I ended up giving the machine away to a friend later. Obviously I may have just been lucky, and I suppose it also depends on which sort of fault the motor originally had in my case, obviously I have no real way of knowing.

In answer to your last post Chris Re: active low, it would depend entirely on the logic, or logic family (Cmos/TTL/other) as to what actual voltage level is interpreted as a logic low by the circuit, more important perhaps is a clear change between between the states of high and low, you could try and measure this at the appropriate point to see what that change between high and low is, this might give you a better idea of what constitutes a valid Low logic  level actually is

I have not downloaded the recently uploaded manuals yet.

Ps. the back spin trick in the previous post worked by temporarily cleaning the commutator apparently, how long temporary actually is could vary enormously, as I said towards the end of the previous post, the mileage could vary.

Another point which I forgot to mention  ? with some CD players the spindle motor was required to give a little 'kick' on Fok, this needed to be done within a tight timeframe as it generated some frequency feedback signals for the servo and/or syscon, if this didn't happen within that tight deadline then the player would not read the TOC (table of contents) and the disk would be rejected, this was partly why a faulty spindle motor by not reaching a fast enough speed, or kicking in time (dead spot) would also prevent the TOC being read.

So the circuit for the LD-1100 is completely different, the FOCUS LOCK signal I mentioned is on N13-1 feeding pin 6 of Z4 but you may have hit on the problem being the FOCUS ON stuck at 3.4V. I would suggest using your scope set to 1V and DC coupled rather that a meter to see exactly what's happening at pin 30 of Z2.

Sorry, forgot to say that you're not looking for waveforms but using your scope as a logic probe. High will be something above 4.5V and low less than 1V.

Posted by: Jayceebee

I would suggest using your scope set to 1V and DC coupled rather that a meter to see exactly what's happening at pin 30 of Z2.

Not sure I follow you there John, Z2 on the VSOP board, FTS section is an 8-pin dual opamp C4558c. Did you mean pin-3?

Sorry Chris that should have been Z2 on the Cont board, it's the FOCUS ON active low signal directly out of the CPU.