Collaro RC456 (RC54) autochange - no set-down

[indigo.girl]

Hi Everyone,
I'm mending a Collaro RC456 record deck (the 4 speed model of the RC54 listed on the service data index). It is suffering from the apparently common problem of automatically returning the pick-up after as soon as the record drops. It appears to be stuck in a never ending loop. I have recorded two videos so you can see exactly whats going on. It's really tricky to see from the exploded view of the assembly whats missing here - any pointers much appreciated. I will record the solution with lots of photos at the end of this thread so hopefully no-one else will get stuck in future. Thanks

View from top:
https://youtu.be/djrfIUrxfmg

View underneath:
https://youtu.be/IW1Fjkcbq2g

Some close up photos for reference.
Also, location of a spring that was refitted (found detached - hopefully back in correct position)







And photo of mechanism with pick up arm at centre of record (manually placed) vs in resting position:

[Edward Huggins]

Well. it's a good job that pick arm is not landing on that LP and 45 with that 78 stylus selected!! Seriously though, there's a lack of slider/cam engagement that's very common on these. One of the two intermediate wheels, the larger one, may not be engaging.

[stumted2]

Hi,
On looking at your pics and video, it looks very much like when the over arm record shaft is down, there remains a gap between the bottom of the shaft, and the part of the mechanism that controls the cycle of the player, i.e. when records are to be played, that part of the mech is up, but when the last record drops and is played, the over arm shaft pushes down on that part of the mech and finishes the cycle.

In your post, you stated that you had found a spring disconnected, and attached it to where you assumed it should go, I can't help but wonder should that spring be attached to that part of the mech which the over arm shaft should operate, which would then allow it to be in the correct position (up) to allow the correct cycle function as in playing records instead of just lifting the tone arm up, and then just setting it down and switching off.

I hope this makes sense to you, and so sorry if this seems a bit garbled.

Cheers, Ted.

[Audio1950]

I can what the problem is due to!
Look at the last photo, the piece at the very top (the gate) should be flipped up when records are loaded, so that the lever that protrudes through it can travel backwards and forwards freely, bringing the arm with it. However when the overarm has finally dropped, it pushes the lever that allows the gate to drop, so that when the arm returns for the last time, the protruding lever pushes the gate up as it passes, and the lever is then trapped as the gate drops again under its own weight, so the arm cannot come across again. If that "gate" is not free to drop because of gummed up grease, the arm will not stop cycling. In your case, the gate is stuck down, so the arm can't travel across. I remember spending many hours lying upside down on the floor under an RC456 propped up on four piles of books, trying to work the damn thing out!

[john.north]

The big lever underneath when the mechanism is cycling should move up. On the video it didn't move so the pivot is stuck.
John.

[indigo.girl]

On closer inspection the underside of all the parts are filthy - so not surprised things are gummed up.


So I decided to do a full strip down, clean and rebuild of the deck. Its now working great. To help future members I have compiled an annotated photographic record of the rebuild so hopefully no one will get too stuck in the future

Here's the before and after shots. The steps will be uploaded 5 at a time next.

[indigo.girl]

[indigo.girl]

[indigo.girl]

[indigo.girl]

[indigo.girl]

[indigo.girl]

[indigo.girl]

[indigo.girl]

[indigo.girl]

[indigo.girl]

[indigo.girl]

[Audio1950]

Well done! Worth taking all the trouble over, these are superb changers.

[indigo.girl]

[indigo.girl]