Sony PS-D707P Problems

[Old Sparky]

Anyone familiar with this turntable?  They were supplied for use with Sony Stack Systems around 20-25 years ago, and I have one in which the leaf switch which interrupts the motor supply is not being opened when the arm is returned to it's rest.  Besides this, the Cam Gear is jammed and won't rotate.  I have diagrams for the player, but cannot see what is causing these problems, so I suspect that further dismantling is needed. I have removed the metal plate on which is mounted most of the mechanism.  The player works well enough in manual mode, but the motor can only be switched off by turning off the associated amplifier (a TA-D505) there being no on/off switch on the record deck, merely a mechanical 'play/pause' button and 33/45 switch.  I suspect the faults may be related.

[Mike72]

The manual is available from here.....


https://elektrotanya.com/sony_ps-d707_ps...nload.html

[Old Sparky]

Thanks, Mike, I 'll check Electrotanya, but have some service info from Vinyl Engine, though it's not very detailed. (Just downloaded the manual from Elektrotanya, and it's exactly the same as that from VE. I'll have to dismantle & check the mechanism again to see if I'be missed anything. Quite possible!

[Murphyv310]

Nice simple turntables. Remove the cam gear and check the plastic bearing in the centre isn't worn and the cam tracks haven't broken. Make sure the levers are free and not binding. Grease the tracks and centre spindle and cam gear with white lithium grease. You shouldn't need a manual for these, they are about as simple as you'll get.
The basic mech is now around 30 years old so wear is the most likely issues.

[Old Sparky]

I've checked the things you mention, Trevor, and all appear to be O.K. This particular 707 is indeed almost 25 years old, but, having said that, the mechanism works O.K. With the cam gear off, all the parts move as they should relative to each other. What I found was that the gear on the center spindle wasn't engaging the teeth on the cam gear, and, if I gently lifted it so that the two meshed properly, the mechanism functioned. so something has caused the gear to move downwards on the |T/T center spindle. Furher checks needed to determine what's happened.

[Murphyv310]

The cam gear will most likely be worn. It was a common issue when I worked for Sony in Audio from 1992-1997. Just double check the thrust washer under the cam gear centre spindle is there, it was a mod and there was a technical bulletin for it. In fairness it was a bodge for wear of the centre of the cam. If the cam gear has play it's basically goosed.

[Old Sparky]

Thanks for that useful info., Trevor. There's no appreciable play in the cam gear, but no thrust washer there, either. No doubt one could be added. Presumably it should be plastic, or would a suitable thickness & diameter metal washer be O.K. A member of UKVRRR has suggested that there might be a hairline crack in the gearwheel on the Turntable center spindle, which I'll have to inspect under a magnifying glass. There is no thrust washer under the T/T spindle, either. As I've just commented over on UKVRRR, it may be simpler just to either remove the Cam gear or that on the center spindle, and use the deck purely manually, although a revised way of switching the motor on and off would then be needed. My other comment 'over there!' was that, the aluminum platter aside, this Sony deck is much the same, including the use of a small DC motor, as the many Chinese made turntables made in more recent years. The better ones have a full-sized, admittedly plastic, T/T, pitch control, strobeoscope, metal 'S' shape tone arm with adjustable counterweight and detachable headshell, none of which are features of the Sony 707.

[Murphyv310]

I certainly had a couple of turntable drive gears crack on this mech, not common but nevertheless a possibility. The thrust washer was spring steel and would slightly compress once the cam was fitted. The technical bulletin was a generic one for a large range of turntables. They certainly were better than the El cheapo Chinese ones but a poor deck for Sony.

[Old Sparky]

Vinyl Engine may have a copy of that Bulletin, Trevor, so I'll check there, but may be able to find a suitable compression washer if one is needed.

[Old Sparky]

Since my last post, I've removed the center spindle assembly from the deck and discovered that there is indeed a hairline crack in the plastic gear, which is what allowed it to move down the shaft, so it's either, as has been suggested on UKVRRR, glue it in place with Araldite metal, or remove the gear and use the T/T purely as a manual player.