Sharp 'Optonica RP114H' belt replacement?

[Yorkie]

My son has recently bought a Sharp ‘Optonica’ RP114H upright record player, which uses two styli and plays both sides of the record in sequence. (It’s one of several that were discovered in a long since disused warehouse, ‘new in box’ though some thirty years old and are currently listed on e-bay with a 'Buy it Now' price). As is to be expected, after such a length of time the drive belt has perished and is in need of replacement.

He’s got a new belt, and has asked me to look at fitting it for him, but having taken the back off, he can’t see any way of fitting the new belt without a major strip-down. He’s got the user manual but that’s all it is - not a service manual so there are no instructions on belt replacement. Clearly belt wear and tear is inevitable over time and at some point, replacement will be necessary. Thus, I can’t imagine that the turntable would have been designed in such a way that replacement is a complex major operation. I hope I'm not mistaken in that view!

I wondered if anyone on the forum has come across this problem on this particular turntable and has any advice on belt replacement?

I’m hoping that there may be a way of ‘fishing’ the belt around the drive pulley and turntable with some stiff wire, but not having yet seen it, I live in hope more than expectation!

Any advice greatly appreciated.

[Radio Fixer]

Sorry! David I cant help on the belt replacement.

But if it comes to you please take lots of pics and write an article for the BVWS Mag. Most unusual item and I'm sure it would be appreciated.

thanks Gary

[tiv48]

may help
http://www.vintage-radio.net/forum/showt...hp?t=34577
Rob t

[Yorkie]

Thanks for the link Rob. Someone 'over the wall' pointed me to it, but it doesn't actually refer to the RP114H model that my son has, which is simply a vinyl disc player and doesn't also have the tape deck. That said, the turntable part of it looks identical to the RP114H, so arguably, my son's should be a bit simpler.

The post starts off in an encouraging style:

Quote:

Disassembly is not too bad on these...

Remove all the screws on the back (marked with an arrow) you will need a long crosshead screwdriver for these, lay the unit on its back, then remove the screws under the record deck & fish out the large suspension springs, open the front flap & pull the knobs off, then lift off the front (all the guts are fixed to the back) you can then stand the unit up again & lower the record deck for access to the belts (see my pics) you can leave the deck connected, just ease the cables out of their clips...

End quote.

There are certainly lots of belts for sale the world over, but a dearth of info on how to fit them.

We'll be spending the weekend with our son and his wife, so I'll report back after the weekend on whether or not we succeed!

[ed731pdh]

If it's anything like doing a twenty year old Technics dual tape deck, I had to unsolder all the control boards to gain access to the belt drives. Nice sound, pain in the rectum to repair.

[Radio Fixer]

Well you may not like this but ...

On some Zenith radios the drive to the tuning gang is by rubber belt and it is sold as a length. The ends are cut off at an angle and the belt put in place and super-glue applied to one face only before bringing the two halves together. Apparently if you use the correct glue (cant remember the details but a web search should find it) the join is a strong or stronger than the original belt.

So if turntable drive belts are cheap and easy to come by it maybe worth a go if major disassembly is the only alternative.

Don't forget the camera David and please do an article for the BVWS

Gary

[Yorkie]

Well I've succeeded in replacing the belt, but it may be that there is an easier way, although I couldn't find one. The info in purple text on post #4 suggests that access to the drum can easily be gained from the front. I tried to find a way of doing that easily, but failed.

On removal of the back cover, we are presented with a large printed circuit board, various levers, switches and wires, with the drive drum (platter) clearly visible. At first sight, replacement of the drive belt which fits around the periphery of the drum and over the drive shaft of the motor, is seemingly impossible with major work to dismantle the printed circuit board and various other items to gain access to the drive drum, and the owners’ manual doesn’t give any clues as to how this can be done.

However, on closer examination from the front of the player with the front cover opened, there is a small gap around the rim of the ‘boss’ onto which the record fits, and with care, the new belt can be fed around the boss so that it dangles around the boss at the rear of the front panel. (maybe there is a way to remove that 'boss' to make things a lot easier, but if so, It wasn't apparent to me). However, I discovered that with care and patience (lots of each!), the drive belt can be fed onto the rim of the drum and the drum slowly rotated by hand until the belt is completely around the periphery. It helps if two people do this – one to feed the belt onto the drum from the right hand side, and as the drum is rotated anti-clockwise (when viewed from the rear), another person can hold the belt on the rim of the platter and take up any slack.

When the belt is right round the periphery of the drum it can be eased over the motor drive shaft. The drum can then be gently rotated by hand to ensure that the belt is correctly positioned and doesn’t ride off the drum.

It may take several attempts until you succeed but don’t be discouraged – it can be done – I’ve done it! If you have to attempt this task without and extra pair of hands, it might be a good idea to use little tabs of sticky tape (‘Sellotape’ in the UK) every couple of inches to hold the belt on the drum till the belt is in position almost all the way around the drum and can be hooked over the motor drive shaft.

The attached picture makes the process a bit clearer.

Hope that might help someone in dire straits! It might even act as a spur for someone to say 'you can save all this hassle by doing it the easy way, like this'...

[Joe]

Obvious question: Does it work?

- Joe

[Yorkie]

Obvious question: Does it work?

- Joe

Yes indeed Joe - and I have to say that to my ears it sounds superb! Electronic speed control and an excellent spec. (Wow and flutter less than 0.06%). A rare find - 'brand new in box', but stored along with thousands of other electronic and sundry consumer items in a warehouse that's been locked up for at least twenty years like a time capsule. I think there were 35 of them at a 'buy it now' price of £135 on e-bay, but they quickly whizzed off the shelves. (My son collected it in person from Stockport). After having been stored so long, it's inevitable that the belt would be jiggered - I guess there will be 34 other lost souls asking in sundry forums ('fora'?) 'how do I fit a new belt'...?

I guess he could have bought a Dansette for about that much, but quite why anyone would want to is one of life's mysteries. (Like the 'magical mustard cap' myth).

[pwdrive]

Those mustard caps were damn good caps.

Lawrence.