Fidelity Record Player. Wrong fuse in mains plug.

[Viscount]

bought a fidelity player yesterday discribed as not working,on examination the deck was seized up on its shaft some penatrating fluid soon eased things off ,removed platter and noticed some evidence of smoke damage so decided to remove the deck and was horrified to see the motor coils had been completly destroyed im suprised the whole thing didnt go up in flames ,all this because it was fitted with a 13amp fuse ,its a shame because its in superb condition cabinet wise and has the transistor amp (god knows if that is still ok )the obvious message is as ever CHECK THE FUSE RATING

[Edward Huggins]

I've seen all this before. Online sellers seem to have thing about "upgrading" the perfectly adequate original (red/black) mains lead, but then go on to use a 13A fuse. What will you do now, find a repacement BSR deck with the appropriate voltage tap?

[Restoration73]

Any protection offered by the fuse is secondary, its purpose is to protect the supply cable.
A reputable manufacturer would have provided an internal fuse or a thermal fuse in
the transformer or motor-transformer.
Checking cable, plug and fuse should be the first action in repair of a mains operated item.

[toshiba tony]

Hello, does stalling an a\c induction motor cause excessive current to flow through it? And if there is an extra winding to provide a low voltage feed for the amplifier does this collapse when the motor is stalled, simple science I know but I'm a little vague on the theory of electric motors, thank you anyone.

[Rubberfingers]

If the transistor amp is powered from a winding on the motor, before fitting another motor you'll need to check that there is'nt a short circuit in the amplifier which has caused the original motor winding to burn out. (It's highly doubtful that a 3A fuse in the plug would have saved the motor, at best a 3A fuse will pass nearly 5A almost indefinately, which would still be a dissipation of 1kW in the faulty/overloaded winding)

[Viscount]

yes im i little vague on that as well all i know is that it appears that is the case due to the amound of damage to this motor and yes it does have the sec winding,i see your point though, any other thoughts out there ??

[Herald1360]

If you've got room, any compatible motor will do with a separate small TX for the amp supply.

[FIXITNOW]

As its a transistor amp best to try it on a good bench power supply with current limiting as see where it gets you , another motor should not be too hard to find with the correct low voltage tap on it, just make sure it's a tap for transistor amps not valve amps as these are much higher voltage

[Viscount]

Originally Posted by FIXITNOW

As its a transistor amp best to try it on a good bench power supply with current limiting as see where it gets you , another motor should not be too hard to find with the correct low voltage tap on it, just make sure its tap for transistor amps not valve amps as these are much higher voltage

ah thats interesting ,what is the voltage tapping for the transistor amp?

[Restoration73]

A voltage tapping on a motor is provided for the heaters of a valve circuit. For a
transistor circuit, there is a totally isolated winding, typically 18V.

[Edward Huggins]

The most common valve series-heater tap was 90V. That's a white wire on the BSR motor. This will be no good for your transistor amp, so be careful.

[Rubberfingers]

Does the amp have an IC in it rather than discrete transistors?. If so, what is it?. Also do you have a model number for the record player?

[slidertogrid]

If the record player was switched on for a long time with the motor stalled it would overheat and if left long enough burn out the motor winding. I doubt excess voltage would have found its way into the amp though, have a look for any burnt components on the PCB and if there is a chip check to see if it is split or scorched.
If it is the usual Fidelity solid state with the chip amp parts are available and the motor is a common enough type. Usually a blue and brown wire for mains input and two white wires for LT. I have a spare motor if that is that type. Later models had a 20mm fuse in the supply to the motor mounted on the amp PCB.
A picture of the amp PCB and deck will help identify it.
Rich

[Viscount]

Originally Posted by Rubberfingers

Does the amp have an IC in it rather than discrete transistors?. If so, what is it?. Also do you have a model number for the record player?

im afraid no model number on this in fact no makers name either,all i can say is that it is identical to the fidelity it simply says Tansistorised at the top left of the speaker grill ,pics to follow when i get a mo

[Station X]

Is it like the one in this thread by any chance?

https://www.vintage-radio.net/forum/...d.php?t=148163

[Viscount]

Originally Posted by Station X

Is it like the one in this thread by any chance?

https://www.vintage-radio.net/forum/...d.php?t=148163

exterior yes internal no ,my on has transistor line up BC157/BC148/AC176/AC128,pics on there way

[Viscount]

Photos as promised.

[Viscount]

note the component next to the grey cap which has also suffered somewhat

[Station X]

Bridge Rectifier with smoothing cap next to it? Check the PCB tracks from the white leads.

[Restoration73]

The smoothing capacitor may have failed, but I would recommend replacing the metal
rectifier bridge (blue) with a 1A silicon bridge anyway e.g.

https://www.cricklewoodelectronics.com/W10.html