EAR De-Luxe Record Player

[Station X]

Use your meter to check for an obvious short circuit across the HT supply. The resistance here should be infinite, but it'll initially show as low until the capacitors are charged by the meter. This charge will be harmless as the meter's voltage is low. Unplug the motor or remove a valve first to avoid shunt effects.

Opening the capacitor can would effectively destroy it, so there's no point in doing it unless you intend to restuff it. Much easier to fit new caps on a tag strip.

Personally after replacing the rectifiers and resistor I'd power up the player via a Variac or test lamp whilst monitoring the HT voltage. Or I'd use my capacitor reformer to see if the caps will reform. This would also show up any shorts across the HT supply.

[Bigears]

better picture of Burned out Resistor

[Station X]

You need to start doing some testing.

[Bigears]

Graham what value should the Diode be ?

[ms660]

Originally Posted by Bigears

better picture of Burned out Resistor

So far as I can see there's some Brown paint and some Black paint which would make it a 100 Ohm +- 20% resistor (as manufactured)

Lawrence.

[Station X]

Originally Posted by Bigears

Graham what value should the Diode be ?

I've never had any trouble using 1N4007's, but some members prefer UF4007's

It would be a good idea to test the windings of the mains and output transformers before going much further. If they're faulty they'll be expensive to replace.

[DMcMahon]

Originally Posted by Station X

When you fit the new diode make sure that the MARKED end goes to the resistor.

Ken, the marked end of the diode (which is the cathode) is the same as the line/bar on the diode symbol on the schematic.

David

[Bigears]

Hi Guys
I've removed the old burned out Resistor and the two rectifiers, do I need to remove the two metel brackets also, I have ordered a diode and a 150 ohms 10w Resistor, am I right in thinking one end of the diode goes to the red wire and the cathode - to the resistor and the other end of the resistor to the green . in picture, also I have purchased a Frolyt Cap 50uf 12/15v 70c to replace Red /Yellow Plessey 50uf 12v 70c, an I right to think the Black is negative

[Bigears]

Originally Posted by DMcMahon

Ken do not forget that there may well be a problem component downline of R16, i.e. the root cause of one of the metal rectifiers sparking and also possibly why R16 is well cooked.

Could this problem accorded if the Turn Table had seized up, as this item is from a Car Boot sale.

[DMcMahon]

I doubt it, the turntable motor load is on the input side (Anode) of the diode.

David

[DMcMahon]

Originally Posted by Bigears

Hi Guys
I've removed the old burned out Resistor and the two rectifiers, do I need to remove the two metel brackets also, I have ordered a diode and a 150 ohms 10w Resistor, am I right in thinking one end of the diode goes to the red wire and the cathode - to the resistor and the other end of the resistor to the green . in picture, also I have purchased a Frolyt Cap 50uf 12/15v 70c to replace Red /Yellow Plessey 50uf 12v 70c, an I right to think the Black is negative

You can remove the brackets if you want to.

I think you are correct about the connections but double check it all to make sure the connections match Lawrence's schematic.

In this case the black end of the capacitor is the positive end (+ve), the plus (+) +ve sign is at that end.

David

[Bigears]

thanks David

[Bigears]

Hi Guys

I've replaced the burned out resistor with 150 Ohms 10 Watt vintage wire wound ceramic resistor and a 1N4007 Diode as in picture and one of the yellow and red Caps with a Frolyt 50uF 12/15v 70C is so far okay also would that new resistor smoke a bit as its new?

I need to do some more testing before I fire it up

Regard Ken

[Station X]

Is that tag on the transformer mounting screw insulated or connected to the transformer frame?

[Bigears]

Its insulated, however back to square one fired up and the new resistor over heats and burned off the solder to the diode, seems live too much power is going to the resistor, its hard to follow the schematics as I am not sure what relates to what as the board is so compacted.

[Station X]

As I've said before, resistors don't cook unless they're passing excess current and they won't do that unless there's a problem with another component.

You have a problem down stream of the resistor. Check the resistance across the HT rail. I suspect you're going to find it's close to zero ohms, in other words a short-circuit.

[ms660]

So far as I can make out the replacement rectifier shown in the 2nd photo in Post#53 looks to be connected the wrong way round...

Lawrence.

[Bigears]

so the diode should go on the green wire and the resistor to the red?

[ms660]

Originally Posted by Bigears

so the diode should go on the green wire and the resistor to the red?

To keep the circuit as original the Green wire should be connected to the anode of the rectifier diode, the cathode (the band end) should be connected to one end of the surge limiter resistor and the other end of the surge limiter resistor should be connected to the Red wire.

If it's been powered up with a reversed connection on the rectifier I would replace the rectifier again and also replace the HT reservoir and filter capacitor at least and make sure the surge limiter is still ok.

Lawrence.

[Bigears]

is this right Lawrence