Technics SLP1200 CD Question

[sp10mk11]

A friend of mine has asked me to have a look at his SLP1200 a 1980s machine

It wont play anything, but my question is does this machine spin the disc on closing the door, (there is only one 3pin switch on the transport which all three pins are shorted when the door is closed) or does it wait for a signal from the laser before it spins the disc

I can hear the laser trying to read the disc but no movement from the spindle motor, the motor is a mini direct drive one

Gary

[tommy6206]

The disc should spin up when the door is closed.Make sure the laser mech lock has been disengaged under neight the unit.

[sp10mk11]

Hello Tommy
Thanks for that, this one doesn't spin at all, I checked the two surface mounted caps on the board and they are ok as are the three bipolar caps, I tried searching for the motor control IC but its no longer available.

Gary

[tri-comp]

Imho there wasn't ever made a CD-player that would spin the disc before the laser obtained focus lock-in with the disc.
If I'm right about that the 'clicking' sound made by the laser is when it tries to focus.
When in vain suspect the laser of being faulty.
It MAY be something else causing the lack of focus, like obviously a dirty lens.
In Pioneer multi-CD's the laser pick-up assembly rubber mounting bearings may collapse and cause loss of focus but I believe the SL-P1200 isn't suffering from this particular problem.

rgds,

/tri-comp.

[sp10mk11]

Hello Tri-comp
All I ever did with Pioneer CDs back in the day was swap out the spindle motors, we used to keep a good stock of them, pioneer even provided a plastic spacer on the chassis you could use to set the platter height

Yes you are probably correct about the laser picking up a disc before it spins, I just had a feeling some worked the other way round.

If I spin the disc by hand you can hear the laser trying to focus on it

if I could get hold of another spindle motor PCB it would make life easier.

Gary

[saxmaniac]

I had one of these and I am sure that the disc spun for a second or two on shutting the door. The display would then show tracks on the disc. Mine had the same symptoms and it was a faulty laser which was unobtainable. I gather this is a common fault.

[sp10mk11]

Hello
This has a working 2nd hand laser in it( taken from a working machine), but it has the same non spinning disc problem as it had with the original laser.
I have checked the voltages on the spindle motor IC etc and they appear to be correct, I have replaced the 5 electrolytic caps, occasionally just occasionally the motor seems to start in a jerky fashion for about 1/2 a turn, or if you spin it the motor appears to control itself for a moment and then stop.
I wish it had one of those cheap can motors and not this mini direct drive one. I know some of the upper range Technics of the period used the same sort of direct drive motor but I cannot think of model numbers

Here is a not very good picture of the transport showing the spindle motor incase it jogs any memories

[tommy6206]

Its more than likely the door switch at fault.I had the same problem with one of mine.

[sp10mk11]

Tommy

The door switch is just 3 prongs that all shorted together when the door is closed, it has a tiny metal plate on it that does this, and by shorting them together the laser then fires up to read the disc, I wish there were more switches on the mech but no only that one.

Thanks
Gary

[tommy6206]

If the laser has been changed or messed with in any way .If so has the spindle height adjustment been re-adjusted. This can be done from underneath the unit. If not adjusted right it will not spin .Ill send you a PM with my home number.