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Denon DRA-685 Remote Volume

 
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OldAudio
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PostPosted: Sun Sep 27, 2009 8:54 pm    Post subject: Denon DRA-685 Remote Volume Reply with quote

Hello,

I replaced the two 1 Ohm resistors in the +&- 15V lines as Mitch suggested and the "Protection" problem was solved, Thanks Mitch.

Now the volume control will not rotate when using the remote. The volume works fine if turned by hand, but not with the remote, however, the display changes in db as the remote volume buttons are pressed, therefore, the receiver is responding to the remote, and everything else on the remote is working. I checked for +&- 15V on the volume board and it is there, but there is no voltage at the volume up & volume down pins to ground when I use the remote. I have performed a reset (holding the tune up & down buttons when applying power) with no change on the remote volume problem.

Any help would be greatly appreciated!

Thanks,
Dave
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vtech



Joined: 08 May 2006
Posts: 1264
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PostPosted: Tue Sep 29, 2009 1:58 am    Post subject: Reply with quote

Back up to the driver IC and all the way to the microprocessor. You should be able to see some activity on the lines going to motor drive IC.
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jts1957



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PostPosted: Tue Sep 29, 2009 7:40 am    Post subject: Reply with quote

A defective motor itself could also cause. Wink
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OldAudio
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PostPosted: Thu Oct 01, 2009 1:35 am    Post subject: Reply with quote

Thanks for the info. I'll check out your suggestions and let you know what I find.
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PostPosted: Sun Oct 04, 2009 5:23 pm    Post subject: Reply with quote

I traced back to the input of the motor control IC (SIP #BA6209N) pins 5-6 and do not see a logic level voltage when using the remote. These are the input pins for the logic output directly from the microprocessor. I pulled the chip and checked for voltage output directly from the microprocessor when using the remote, and there is "0" volts. I am now assuming that the up/down output control portion of the microprocessor is open as it measures 25k to ground with power and/or signal on or off.

If there are no other possibilities, I'll probably sell it cheap with the understanding that the remote volume is not working, but everything else is fine.
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vtech



Joined: 08 May 2006
Posts: 1264
Location: USA

PostPosted: Tue Oct 06, 2009 2:09 am    Post subject: Reply with quote

Anonymous wrote:
I traced back to the input of the motor control IC (SIP #BA6209N) pins 5-6 and do not see a logic level voltage when using the remote. These are the input pins for the logic output directly from the microprocessor. I pulled the chip and checked for voltage output directly from the microprocessor when using the remote, and there is "0" volts. I am now assuming that the up/down output control portion of the microprocessor is open as it measures 25k to ground with power and/or signal on or off.

If there are no other possibilities, I'll probably sell it cheap with the understanding that the remote volume is not working, but everything else is fine.


Have to say that while it is always a possibility, it is rather odd for just two of the ports to be bad! Not sure of the 25K reading but it can't be open; if anything it is rather leaky/shorted. Just make sure it is not something on the trace or either connector ends.
Short of replacing the processor, Just about the only other thing would be a reset which I doubt will have any effect but worth trying.
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