Garrard 'Unimech' deck mechanical fault

[Old Sparky]

PlusGas certainly seems to have done the job with regard to the Trip Pawl on the 6-300 deck, Trevor. Haven't yet tried it on the speed-change mechanism, which includes plastic parts (hopefully it won't affect them adversely), or on the Cam Gear, which turns reasonably freely anyway.

[Murphyv310]

Never had any problem with plastics with Plus Gas. I've been doing car repairs for years and use Plus Gas a lot and any plastic covers or other plastic items have never been damaged or shown any signs of melting or disintegrating.

[Old Sparky]

I'm still having problems with the 6-300 deck. Despite applying Plus-Gas to all accessible parts of the speed/size change mechanism, it is still seized, and I can't see which part(s) are jammed. I'm reluctant to dismantle the mechanism as it involves removing the pick-up arm and several other parts. Individually the various parts seem free to move, except the selector lever which can only be moved a few mm. Any ideas, anyone?

[Murphyv310]

Unfortunately a stripdown may be the only answer. If you don't have an exploded diagram, take lots of photos and when dismantling try to keep every thing in order. Often once you've done the job its all assembled you'll say that wasn't so bad.

[Old Sparky]

Thought it might come to that, Trevor. I do have the manual, courtesy of Vinyl Engine, b.t.w.), but I'll speak to the owner before taking the mechanism apart.

[Old Sparky]

Despite my checking that the pickup arm is free to swing, and that it's wiring isn't fouling anything, and fitting a new stylus, the player is still prone to mistracking, where the stylus will either stick or jump (usually the former) at some random point anywhere during the playing of any stereo LP. IMHO, this is due to either friction in the mechanism - the speed/size selector is still stuck in the 12"/33rpm position- or to the, again IMHO, the poor way in which the M75 cartridge, is held in place in the PU Head - a simple clip, which barely grips the sides of the cart.-is used. The Shure M75 cart. and fixing clip are mnufacturer's original fitting, b.t.w. Garrard seemingly supplied the 6-300 decks to Dynatron, fitted with the M75 cartridge. N.B. - as I think I mentioned in an earlier post the tracking weight is set to 4g (measured with my trusty old Garrard SPG!), and the ant-skate is also set to th4 4g. click-stop position. Maybe reducing both to 3g would help?

[Old Sparky]

The more I read, and hear, about the 'Unimech' decks (described recently on a thread over at UKVRR, the more I wish I had a drop-in replacement of a different model and/or make for that fitted to the Dynatron stereo in question!

[Murphyv310]

The Garrard AT6 was a good enough autochanger, the idler type drive being its weak point, the earlier SP25 versions are virtually identical.

[Old Sparky]

The dynatron is now back with it's owner, still with the 6-300 deck fitted. He has been advised that either a complete stripdown, cleaning & re-lubrication of the existing deck, or a replacement, preferably of a different model, is required.