CCL Capacitor for Deccasound 600

[Robint 47]

The A600 is part of the Deccasound 604 system which is now on Disc2.To m y knowledge Decca have never fitted a resistor to lamp circuit which is 6.3V. It cannot be seen what Tx is fitted which is why i suugest return to original spec Robin

[ysgramor87]

Originally Posted by vinrads

Just to confirm there needs to be 28 volts on the fuse , any 8 ohm speakers will do must be 8 ohm . Mick.

I'll try to measure within an hour. I hope I can manage to do it.

Thanks Mick.

[ysgramor87]

Originally Posted by vinrads

Just to confirm there needs to be 28 volts on the fuse , any 8 ohm speakers will do must be 8 ohm . Mick.

Hi Mick,

I've measured 5V on fuse.

0 V on red and yellow terminal of big capacitor. As you've said, black cable goes to ground and pinky cable comes from choke.

0 V on two terminals of choke.

I hope you can make comment on my measurements. Thank you so much again.

Cheers

Fatih

[Station X]

Originally Posted by Robint 47

The A600 is part of the Deccasound 604 system which is now on Disc2.To m y knowledge Decca have never fitted a resistor to lamp circuit which is 6.3V. It cannot be seen what Tx is fitted which is why i suggest return to original spec Robin

Thanks for that Robin.

I've attached an extract showing the PSU section of the circuit.

As has already been stated it's suggested that the OP restores the wiring to original spec then checks the DC voltage on both positive tags of the cap. If only one tag has voltage on it, then the smoothing choke is a likely suspect.

I suggest removing the internal fuse before doing the test.

[Station X]

Originally Posted by ysgramor87

Hi Mick,

I've measured 5V on fuse.

0 V on red and yellow terminal of big capacitor. As you've said, black cable goes to ground and pinky cable comes from choke.

0 V on two terminals of choke.

I hope you can make comment on my measurements. Thank you so much again.

Cheers

Fatih

How odd!!! You've got 5V on the fuse, but nothing on the choke. THESE POINTS ARE CONNECTED which suggests you have a wiring fault.

[Cobaltblue]

The transformer does not look like the original to me it looks as if this has had a faulty transformer replaced.

Cheers

Mike T

[Michael Maurice]

There should be around 28V on two tags of the capacitor, if there isn't the choke, which looks like a small transformer could be open circuit.

I have attached a small part of the circuit which shows the capacitor block and the choke.

Almost certainly the modules are faulty. Remove Fuse 1 which is the supply to the amplifier modules and try measuring again.

[ms660]

I might be wrong but it looks like the DC fuse has been connected to the +ve wire of the rectifier, photo's 1 and 4 in Post#23.

Lawrence.

[Michael Maurice]

Unfortunately there seems to be so much butchery that we can't tell what is original and what isn't.

It would be helpful to know what the transformer is in terms of output voltage and VA.

[ms660]

The Orange wire from the rectifier appears to connect to the fuse unless it's sneaking off somewhere else, the Brown? wire from that fuse looks as though it connects to the reservoir capacitor and the choke.

The transformer looks to be an RS dual 115v primary and a dual secondary, the primaries are connected in series (Yellow jumper) and the secondary's appear to be connected in series (the other Yellow jumper) One of the secondary windings appears to feed the bridge rectifier and the other appears to feed the bulb via the 50 ohm resistor.

......So far as I can make out.

Lawrence.

[ysgramor87]

Thank you everyone,

I'll try to do you suggestions. I might need professional help anyway. Would be perfect if I could watch during servicing

[Station X]

Perhaps someone decided to put the fuse where it says '28' on the diagram? Doesn't explain why there's only 5V on the fuse though.

[ms660]

Originally Posted by Station X

Perhaps someone decided to put the fuse where it says '28' on the diagram? Doesn't explain why there's only 5V on the fuse though.

That's where I think it's connected to as suggested earlier, if you look at the photo's you can see what I mean.

Lawrence.

[Station X]

Yes. I should have quoted your post. I was agreeing with what you said.

[Cobaltblue]

Hi Fatih

Maybe its time to take some good pictures around the mains transformer, rectifier, fuse and capacitors so we can work out what has been done and if it's OK.

It's always a bit more difficult when there have been replacement parts fitted and some of the work looks suspect.

Cheers

Mike T

[ms660]

Can't see the rectifier markings but it's connected as chamfer to load -ve.

Lawrence.

[Michael Maurice]

Originally Posted by ysgramor87

Thank you everyone,

I'll try to do you suggestions. I might need professional help anyway. Would be perfect if I could watch during servicing

Please PM me or look at my website if you require help, but please remember social distancing.

[ysgramor87]

Originally Posted by Cobaltblue

Hi Fatih

Maybe its time to take some good pictures around the mains transformer, rectifier, fuse and capacitors so we can work out what has been done and if it's OK.

It's always a bit more difficult when there have been replacement parts fitted and some of the work looks suspect.

Cheers

Mike T

Hi Mike,

I'll do it and try to draw it as well

Thank you,

Fatih

[ysgramor87]

Originally Posted by Michael Maurice

Please PM me or look at my website if you require help, but please remember social distancing.

I'm very happy that you might be very close to me I'll try a bit more then we can contact.

I'm NHS worker, I have covid test very often

Cheers

Fatih

[Station X]

I know lots of advice has been given, but I suggest the first thing you do is check the continuity of the choke. If it's open circuit it could be a show stopper.