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

[Bert 1100]

Oh dear,

So now the switch fault finding/testing begins? Hmmm

I think you should be very happy if it turns out it's the switch.....

 

[Steven Tate]

Be SURE the unit is unplugged when you work with the switch. It has full AC voltage on one side all of the time and is dangerous if plugged in.

 

[rBuckner]

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.

It looks like an original one.

Here's an easy check before digging into the bridge rectifier. With the switch off is there a dead short across the power cord prongs?

 

[bberkom]

It looks like an original one.

Here's an easy check before digging into the bridge rectifier. With the switch off is there a dead short across the power cord prongs?

Here's a pic of my 1060. The switch on the OP's unit is not original. It should be a metal push button just like the rest of the switches, not a red plastic switch shown in his photos from his original post. Not saying it's even the most likely culprit, just something I'd want to take a look at since it has been replaced.

 

[Homer4beer]

It looks like an original one.

Here's an easy check before digging into the bridge rectifier. With the switch off is there a dead short across the power cord prongs?

Thanks,

So with the unit unplugged, and the switch off, put a multi meter across the terminals and if I have continuity with the switch off it's faulty.

Yes?

 

[petehall347]

yes correct .
also try with switch on and measure the ohms .
i guess the fuse was only blowing when powered on .if so switched on is the way to go . still unplugged though .

 

[rBuckner]

Here's a pic of my 1060. The switch on the OP's unit is not original. It should be a metal push button just like the rest of the switches, not a red plastic switch shown in his photos from his original post. Not saying it's even the most likely culprit, just something I'd want to take a look at since it has been replaced.
View attachment 904275

Oh yes, of course you're right! I was looking at Bert's post, not the OP's. Duh me!! I agree with you.

 

[Homer4beer]

I've bypassed the switch and simply soldered the wires together. When I turn the amp on the DBT still burns bright and never dims.

So I've got to test the bridge rectifier. I've read about how they work and looked at electronic education websites but they don't look anything like this:-(

Any help?

Ta

 

[petehall347]

wiring doesn't look quite right but might be the pic.
if you disconnect the inner AC wires and insulate them it should power up and bulb should dim .
to test it you need to remove all 4 wires .best see if bulb dims first with AC wires disconected.

p.s the schematic you posted looks nothing like the 1060 one i have here

 

[Homer4beer]

Thanks Pete,

The schematic I posted is this one https://www.hifiengine.com/hfe_downloads/index.php?marantz/marantz_1060b_service_en.pdf

I think this may be the one you have? https://www.hifiengine.com/hfe_downloads/index.php?marantz/marantz_1060_schematic_imp_scan.pdf

So I disconnect all the wires from the middle two terminals which has the "Z" icon on it (A/C I suppose?) so those terminal do not have any wire attached to them. Then I insulate them, power up and see if the bulb dims?

Cheers,

Again many thanks for walking me through this process!

 

[petehall347]

you have the b manual . is yours a b ?
and yes disconnect those wires

 

[Bert 1100]

Hey, yes beware, you have the 1060, NOT the 1060B....I didn't even know the B existed....they are most likely completely different....

 

[Homer4beer]

Thanks guys,

I'll delete the 1060B manual now so I don't confuse myself!

 

[Homer4beer]

Good news guys!

It seems the bridge rectifier is cactus. I've taken the 2 middle wires off it and now when I use the DBT it dims nicely as it should

So where do I buy one of these to replace it with?

Cheers guys

 

[petehall347]

now to be sure about this put the wires back and remove the 2 outer wires and see if lamp dims . if so measure the voltage between the empty pins .

 

[Homer4beer]

Ok ta.

Job for tomorrow

 

[restorer-john]

Good to seed you built your DBT over the weekend!

I have replaced those old International Rectifier bridges in several 1060s in the past. They get oxide migration up the legs and into the semiconductor junctions (notice the black legs).

There is a suitable mounting point for a normal square bridge rectifier close enough so you can use the existing wire.

 

[Homer4beer]

Good to seed you built your DBT over the weekend!

I have replaced those old International Rectifier bridges in several 1060s in the past. They get oxide migration up the legs and into the semiconductor junctions (notice the black legs).

There is a suitable mounting point for a normal square bridge rectifier close enough so you can use the existing wire.

Yep cheers. I'm not sure where to find one local. Probably Jaycar?

I'm in Brisbane

 

[Homer4beer]

Guys can somebody please let me know what to buy for this job?

Thanks...a bit lost again

Something like this ok? Will is suit and fit?
https://www.jaycar.com.au/400v-35a-bridge-rectifier/p/ZR1324

Or more like this?
https://www.jaycar.com.au/po4-6a-400v-bridge-rectifier/p/ZR1314

 

[Bert 1100]

now to be sure about this put the wires back and remove the 2 outer wires and see if lamp dims . if so measure the voltage between the empty pins .

Before you go and find a new rectifier, you need to know if it is bad or not....did you try what petehall suggested ?