View original (French)

Repair of a REVOX

chastinou Posted messages 38 Registration date   Status Member Last intervention   -  
 yveslyon -
Hello, I’m not sure if I’m on the right forum: my REVOX B77 MK II has a playback issue, the drive shaft is not turning anymore, yet it’s not stuck because if I "force" it a little manually, it turns. However, fast forward and rewind work just fine. Can anyone tell me where this might be coming from? It hasn’t been used for several years; I’ve cleaned the heads and used a blower, it’s clean. Can anyone help me please? Thank you. 
Configuration: Windows XP Firefox 3.0.5

5 answers

  1. Galaad_di_corsavy
     
    The motor drive failure of the capstan may be due to a failure of the 21V power supply or the speed regulation board of the motor.
    It is necessary to check and replace the electrolytic capacitors; do not forget the clear plastic type 0.47uF 250V capacitors soldered onto the capstan motor regulation board. The 2 diode bridges on the power supply board are aging, causing the device to consume more. Don't forget the capacitor located on the device's power input.
    Components deteriorate faster when the device is not in operation. You can repair it yourself; you will need the technical diagram, a good soldering iron, and patience.
    9
    1. chastinou
       
      Hello, thank you very much for taking the time to respond. I sold it as is, but I take note of your information.
      0
    2. adtridan
       
      Hello,
      I am reaching out to you because, unlike some, you seem to have a good understanding of this type of equipment.
      After many years, I have just managed to get a B77 running again. After noticing that nothing was working, a large puff of smoke escaped.
      I opened it up to find that the electronic component connected between the mains socket and the fuse holder had burned out.
      I believe (and I hope) that I can find this component without too much trouble, but what worries me the most is that while handling the device, small pieces of notched plastic fell out that could resemble pieces of a belt...
      These pieces are 2 mm wide. As soon as I touched them, they broke into tiny bits like plastic that has often been "hardened" by time.
      To your knowledge, is there any component in a B77 that could use or be driven by a small belt?
      Best regards.
      0
  2. yveslyon
     
    Hello
    On the REVOX B77, the small pieces of rubber come from the toothed belt that drives the tape counter.
    As for the motor regulation board, there is one for sale on eBay at the moment.
    http://cgi.ebay.fr/ws/eBayISAPI.dll?ViewItem&item=260793509201&ssPageName=STRK:MEWAX:IT#ht_1416wt_751

    Best regards
    Yves
    1
  3. Delta
     
    Hello, the fact that the drive shaft no longer turns is due to a derailment or the breaking of the belt that drives it. Nevertheless, this does not prevent your tape recorder from fast-forwarding or rewinding.
    0
    1. titi
       
      Pfff no belts on the Revox
      When you don't know anything, you shouldn't respond.
      -1
  4. thierryg
     
    The engine training control board of the Cabestan must be faulty.
    You can find one at MVT, rue Legendre in Paris.
    Check first if one of the two small fuses next to the power supply is not blown. You just need to remove the 4 screws on the back of the cover and take it off to access it...
    0
  6. chastinou
     
    Hello, thank you, but I sold it as is.
    0