Marantz CD80 tray motor is running non-stop

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Jump to Latest
J

Jeph

Member
Joined 2003
I have a modified Marantz CD80 that I have used for years without any troubles, but now the tray motor refuses to switch of. It is permanently trying to pull the tray in, and there seems to be no problem with the switches.

I thought the source of the problem was a dirty connection, because it went away for a couple of weeks after I had taken the main circuit board out and put it back in. But now the problem has returned.

I would really appreciate your help. Thanks in advance.
:)
 
G

Guido Tent

Member
Joined 2001
TentLabs.com
Jeph said:
I have a modified Marantz CD80 that I have used for years without any troubles, but now the tray motor refuses to switch of. It is permanently trying to pull the tray in, and there seems to be no problem with the switches.

I thought the source of the problem was a dirty connection, because it went away for a couple of weeks after I had taken the main circuit board out and put it back in. But now the problem has returned.

I would really appreciate your help. Thanks in advance.
:)
Click to expand...


are you sure the end-switch makes contact ?

otherwise I suspect a defect transistor in the bridge driving that motor, any chance to measure the control signal ?

best
 
G

Guido Tent

Member
Joined 2001
TentLabs.com
Jeph said:
Yes, the switch is ok. I can't seem to find a bridge, but the drive to the motor apparently comes from an operational amplifier called TCA0372(A)? Please let me know what I should be looking for.

All help is greatly appreciated. Thanks.
Click to expand...

Hello Jeph,

Good. I asked it expicitely as I have been fooled once by my own observation - switch closed, but no contact.....

We certainly need a circuit diagram. I am at home now, but will look at the lab if I can dig up some. Otherwise Jean-Paul could be contacted.

best
 
Jocko Homo

Jocko Homo

RIP
Joined 2002
Minus .58 V????????? How can that be........only +5 on the micro.......unless............

On the bottom of the PCB, there is a zero ohm jumper.........3318, and it goes to 3319.......2.7K. Try scraping off that smd jumper, and ground the junction point. See what happens. Measure pin 21.

(Pull the connector that feeds the tray motor............)

Jocko
 
G

Guido Tent

Member
Joined 2001
TentLabs.com
Jocko Homo said:
Minus .58 V????????? How can that be........only +5 on the micro.......unless............

On the bottom of the PCB, there is a zero ohm jumper.........3318, and it goes to 3319.......2.7K. Try scraping off that smd jumper, and ground the junction point. See what happens. Measure pin 21.

(Pull the connector that feeds the tray motor............)

Jocko
Click to expand...


Hi Jocko

same thoughts across the world :) (see post below)

-0.58 is a reverse biased protection diode inside the uC

best
 
J

jonclancy

Member
Joined 2002
Hi,

Did you ever find out what the problem was here?

This tray control is the same setup used in the Arcam A6 CDP. I'm having a similar problem except the motor overruns for a couple of seconds on the +5V opening. Limit switch is only used for the tray closing in this implementation.

All the best

Jon
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Top Bottom