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This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022

 

Beocord 7000 dead after recapping / belt change

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Micromarc
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Micromarc Posted: Wed, Feb 2 2022 2:20 PM

Hi Forum,

I am Marco from germany and a newbie to this forum. I recently bought a broken Beocord 7000 and ordered the three belts for the tape mechanism. As the player arrived I checked it's functionality:

  • it turned on after pressing PLAY
  • it opened the tray after pressing OPEN
  • when PLAY pressed some clicks happened, but the tape didn't spin
  • when FWD or RWD pressed also clicks happened, the display showed the action FWD or RWD, but also no tape spin.

I thought that was a slipping or missing belts problem, so that the mechanism controller turns the motor off, because it senses no motion from the tapereels. I changed the belts (managed to fiddle the flat belt in without desoldering the small pcb), all old belts were present. As I was in there I cleaned all belt pulleys with IPA and pulled the two spindles, cleaned the tips and shafts and rubbed the shafts with an oil soaked towel, so that they move smoothly. After I put the mechanism back in and powered up once again there was less functionality:

  • when pressing FWD, RWD or PLAY the device powered off

I looked upon the internet to get some resources / further information about the device and only found a owner's manual for BC 7000 and a service manual for BC 5500 and BC 6500, sadly no SM for the 7000.Crying

I decided to recap the whole device, since I was going to do it anyways and wait for the behaviour of the player after that, assuming there can be issues with the supply voltages because of dry caps.

When replacing the caps I noticed several inconsistencies of the part labels on the PCB between top and bottom labels, so I documented every single cap and double checked it's orientation. If anyone needs a list of the capacitors let me know, I'll post them here.

And now I am here, not because the player works as it should. The behaviour is still the same and I need to go more in depth with the circuitry.

Since I haven't got the right SM, only BC5500 and BC6500, I looked at the control circuit and the power supply. Between BC5500 and BC6500 are differences in circuitry (i.e. motor supply 14,8V and 12V) and the connector to the PCB2 is different.

My questions:

 

  • has anyone the correct service manual?
  • has anyone a clue of common faults for this deck and could point me in a direction?

 

stay healthy,

Marco

Dillen
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Copenhagen / Denmark
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Dillen replied on Wed, Feb 2 2022 2:32 PM

Beocord 5500, 6500 and 7000 are basically identical, so the service manual for Beocord 6500 will also apply to your deck.
Having said that, both models were produced with two different set of internals (different tape drive, controller etc.) so make sure you are looking
in a manual covering the second tape drive version.

Martin

Micromarc
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Hi Martin,

thanks for the quick reply! I just now entered work on the deck after posting. I took the mechanism out to test the motor with a 12V power supply and looked for similarities of the pcb and the sm. First I was confused of looking at a 13pole connector and read of a "P16" (that is what left me suspicious), but that seems to be right. Then I found R171, what should be 2R2 and I am probing 22R.

Then you replied and yes, I have the manual of the "tape deck version II". So now I will start investigations, thank you!

Marco

 

Edit: a weak battery in my voltmeter tricked me here: R171 is fine, motor is also spinning with external 12V. On we go...

Micromarc
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Update:

the behaviour is slightly different than I posted last. The deck doesn't turn off. It just does nothing, wenn RWD, FWD or PLAY is pressed. One can see a LED lighting up when buttons are pressed, just like a remote signal is received but there is no further action. When I press TURN the state of the cassette side briefly switches to 2, but immediatly switches back without any action of the mechanism.

I measured the voltages on P6 and P5 coming from board 1:

  • P6/8: 15,74V (target: 15,5V)
  • P6/9: 15,22V (target: 14,8V)
  • P6/3: 25,7V (target: 22V)
  • P5/1: 5,04V (target: 5V)
  • Emitter of TR38 is 12,5V, but solder joint "+" on the motor is 0V - how is the motor controlled?

I also checked polarity and values of all nine capacitors on board 2 again and they are all correct.

Marco

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