Marantz cd6000 faulty

[barry.childs]

Hi, I have a Marantz cd6000 ki. It has cracked open a diode in the power supply circuit and the transformer is running hot. There is no display and no sound. I suspect a reg or transistor or poss cap. Can anyone help as I cannot plug it in to check anything. Just need an idea of where to look! Any help would be appreciated. Thanks Barry

 

[Mooly]

Hi, I have a Marantz cd6000 ki. It has cracked open a diode in the power supply circuit and the transformer is running hot. There is no display and no sound. I suspect a reg or transistor or poss cap. Can anyone help as I cannot plug it in to check anything. Just need an idea of where to look! Any help would be appreciated. Thanks Barry

It was an Arcam last time around wasn't it

It would be a big help to see a circuit, however without you need to to first see what the diode feeds directly... cap, regulator etc which you suspect.
I take it one end of the diode goes to the mains tranny, in othe words just a normal rectifier application.
Take the diode out and read on ohms across the cap it feeds... you never know what that might show... probably nothing but it has to be done.
There's a 70% chance that just replacing the diode and electroylitic and reg assuming that's what it feeds will fix it. Any 1amp diode should be OK to fit as a test such as IN4004 etc.

Edit... remembered this thread... not quite the same model but no display... is it the same diode of the PSU ?
http://www.diyaudio.com/forums/digital-source/147694-marantz-cd5000-display-very-dull-help.html

 

[barry.childs]

Hi Mooly, I'm glad you remembered. It is a simple circuit from the transformer. There are 4 diodes, 8 caps and a pair of regulators for -12 and +12. Unless of course it is whatever they are feeding that's at fault. Iv'e replaced the diode, but still the trany is hot and nothing works. I will get new regs and check the caps tomorrow and let you know how I get on. Cheers Barry

 

[picowallspeaker]

Could happen to be ROASTED the trany . May a thin wire that brings power to the crystal display ,to be burned ,or not ...that is the question !
I would check the secondaries before desoldering anything else...
well ,at least only one leg a diode

 

[barry.childs]

I hope it's not the trany. I'm too scared to try it. I did replace it to start with, with a trany from a cd67 and that didn't work. I'm pretty sure they are interchangeable but not certain. The ki has a pretty toroid which I would have a job replacing I think.

 

[Mooly]

Trannys are pretty tough... until the insulation melts it will survive. Take the diodes out, see if the tranny still gets hot.

4 diodes wired as a bridge ? replace all 4 and all electroylitic caps they feed together with the regs.

Manual from here,
http://www.hifiengine.com/manuals.shtml

 

[barry.childs]

I have ordered new diodes, regs, caps and transistors (there are four very near the diodes) from RS. Should get them tomorrow when I will report back. Cheers Barry.

 

[Mooly]

OK
The manual from the above link is free... have a look. You just need to register.

 

[barry.childs]

That's great Mooly, I will be able to check the transformer voltages now as well. I will wait until I have fitted the other bits, then I will refit the trani but only wire the mains side. I can then check the other side before connecting. Yippy!

 

[barry.childs]

Well I swapped a load of stuff and now it works. Thanks everyone. Next problem is a bit weird. When I open or close the drawer, it only moves a little bit. There is nothing stuck in there and the gearing all looks ok. It's as if it is being told to do that! Any theories welcome.

 

[barry.childs]

It opens until the laser assy drops and then stops.

 

[Mooly]

Did it do that before the other fault, or has this occured since ?

Maybe check the supply to the loading motor driver as it operates. Always check all the supplies as a first thing with any faulfinding.

It's either lack of power (supply voltage) to the motor or something mechanical...

 

[barry.childs]

I don't know if it done it before as I bought it as non working. No-one mentioned it though.
I have a spare mechanism from a cd67 and when plugged in it does the same, so I assume that rules out a mechanical fault. I would have thought if it was a lack of supply to the motor it wouldn't move at all, but it does for about an inch!

 

[barry.childs]

Also in service mode I get error 11. Sledge error. and the sledge does not move. I tried turning the motor and gear by hand but could not so I assume the motor is stuck. Best get a new laser assy and try again.

 

[Mooly]

Never assume faultfinding Measure and be sure. Is it a CDM12.1 or 12.4 ?

 

[Mooly]

You say you tried turning by hand. If it's a worm drive like the CDM12's then you have to turn the motor, you can not turn the toothed gear.

 

[barry.childs]

It's a CDM12.1. Your right, I removed the motor and everything turns. Looks like no power, so perhaps I have a dry joint or forgot to solder one of the regs. I'll check everything again. Nothings easy when your stupid!

 

[Mooly]

Check the supplies... check 5 volts is on the TDA7073 motor drive IC's and that it stays at 5 volts when the motor tries to open the drawer. Also measure directly across the motor to make sure 5 volts is present. If it plays a disc the sled is fine... it's a different motor that opens the drawer.

 

[Mooly]

Are all the fuses OK... a quick glance and it looks like it would "work" with one of them blown... check them. The 5 volts for the motors comes from IC 7114 in the PSU, one of the 7805 regs.

 

[barry.childs]

The fuses are ok. The sled is not working either. The laser is ok. So I presume the voltage for the sled is the same as for the drawer, but being as the drawer opens and closes some of the way, I think my easiest way is to trace the sled voltage. If the same reg drives both I would suspect something around there.