Marantz Model 1060 Amp - main 3 amp fuse blows - help pls

[Homer4beer]

3) disconnect pre-outs to main in

How do I do this?

 

[Homer4beer]

in the amp board
6) try out the pre-outs to another working power amp or amp.

Again I'm totally lost here.
Cheers

 

[Bert 1100]

Again I'm totally lost here.
Cheers

Ok...
At the back of the amp you will find black plastic-covered so-called "jumpers"



What they are is just a very short rca interconnect.
What they do is link the 1060's internal preamp to it's own internal power amp.
The point is that you can use your 1060 as a standalone preamp OR as a standalone poweramp. (more possibilities but let's stay with basics here...)

So with your 1060, if you find that the fault is in the poweramp part, after having removed the "jumpers" you can test the preamp to see if it is working or not.
(As explained before you can remove the power feed to the main amp board and see if it passes the DBT...)

What you need to do is connect the pre-out to another working amplifier with an rca cable.

Do you have another integrated amp or receiver or power amp available ?

Were you able to test your DBT with a working amplifier ?

 

[Homer4beer]

Great response and lots of help.

Thanks Bert.

Yes I've now desoldered the wire you pointed out (it was wrapped around the terminal and then soldered so a little awkward to remove but done).

So I need to power up the amp after removing the jumpers. If the bulb dims the problem is the main power amp.

I do have another amp although I'm not sure if it has pre amp inputs (is that what I need?).

Sorry for the, probably, very basic questions, I've just never used a pre amp before.

My DBT does work.

Cheers

 

[Homer4beer]

No joy Bert,

I've followed your instructions with the DBT not lighting the bulb until I turn the amp on where it just goes fully bright.

No dimming at all.

Where to next? Re solder the wire back on?

 

[Bert 1100]

So, your DBT tested as working with another amp ? first bright then dim ?

And after disconnecting the supply wire to the poweramp board you still get a bright bulb ?

The jumpers need removing only if you want to test the preamp. But here and now it looks like the problem is somewhere else....

No need to reconnect the power feed to the amp board yet. insulate it well and keep it that way until you figure out where the problem is.

 

[petehall347]

looks like it could be a shorted rectifier in the power supply .
H007

 

[Homer4beer]

So, your DBT tested as working with another amp ? first bright then dim ?.

Yes I tested it not on an amp but other things like a PC.

And after disconnecting the supply wire to the poweramp board you still get a bright bulb ?

Yep very bright, normal bulb brightness

No need to reconnect the power feed to the amp board yet. insulate it well and keep it that way until you figure out where the problem is.

Will do!

Cheers

 

[Homer4beer]

looks like it could be a shorted rectifier in the power supply .
H007

Righto.

Where would this be be and how can this be checked?

Thanks

 

[Bert 1100]

Now, I think you need to do a bit of homework for yourself

What comes out of the transformer is AC, what comes out of the rectifier is DC.

do a bit of search on how to test a diode... a bridge rectifier is 4 diodes....

do you have a DMM (digital multimeter) with a diode function ?

 

[Homer4beer]

Lol yes teacher I will research and report my findings

Is your arrow pointing to the black box or the switches in the middle?

But jokes aside I am very grateful for the assistance you all have given me so far!

Cheers

 

[bberkom]

Isn't the power switch on this 1060 non original? Just figured I'd point that out since there seems to be a short in the power supply somewhere. I'd suspect that since someone replaced it with just any old switch.

 

[Bert 1100]

Is your arrow pointing to the black box or the switches in the middle?

What switches ? There are no switches there in the middle.....or should be no switches. The rectifier is the black box with 4 wires, it's screwed to the side of the chassis.

 

[Homer4beer]

Isn't the power switch on this 1060 non original? Just figured I'd point that out since there seems to be a short in the power supply somewhere. I'd suspect that since someone replaced it with just any old switch.

Yes but the switch works and simply closes or opens a contact for current to flow doesn't it? How can this cause the fuse to blow?

 

[Homer4beer]

What switches ? There are no switches there in the middle.....or should be no switches. The rectifier is the black box with 4 wires, it's screwed to the side of the chassis.

I'm on a mobile and wasn't sure if you meant at the end of your arrow tip or further away at the black box.

I did think you meant the black box but double checking to make sure.

So my reading tells me a diode allows current to flow only in one direction and a recifier does the same but in a much higher voltage, generally greater than 1V.

 

[Bert 1100]

I did think you meant the black box but double checking to make sure.

It's a small thing, mavbe 30x30x5 mm. I hope you're not confusing it with the transformer (sorry but it looks like this is all very new to you )

Yes but the switch works and simply closes or opens a contact for current to flow doesn't it? How can this cause the fuse to blow?

Well, if the previous owner knew absolutely nothing about electronics it's not unthinkable he could have wired the switch so that it just shorts out the mains ????

 

[Homer4beer]

View attachment 904164

Now, I think you need to do a bit of homework for yourself

Ah ha! So this is a full wave bridge rectifier yes?

 

[Homer4beer]

It's a small thing, mavbe 30x30x5 mm. I hope you're not confusing it

I think I was confused because it looks silver in the photo but you said black?

Anyway I now know exactly what you mean now

So if I remove the switch and wire it so it's on permanently that would remove the switch as the possible cause (as a temporary measure)

 

[bberkom]

Well, if the previous owner knew absolutely nothing about electronics it's not unthinkable he could have wired the switch so that it just shorts out the mains ????

That's my thought exactly. Never know who's been in there and what they've done to "fix" it previously!

 

[Homer4beer]

Oh dear,

So now the switch fault finding/testing begins? Hmmm