Akai GX-77 belt replacement & tune-up?

Discussion in 'Tape' started by testwork, May 7, 2009.

  1. testwork

    testwork Active Member

    I received a GX-77 recently as part of a purchase of some Bose 901 speakers. It was a "buy it all or nothing" kind of deal.

    The GX-77 is in non-working condition. So I opened it up and I see there is a tiny thin little belt that is broken. I'd like to replace this and also do a basic tune-up with alcohol while I've got it apart.

    Is there just the one belt that needs to be replaced, or are there other belts that I just didn't notice? I could only find one belt on the Internet to purchase for it. But there were occasional references to more than one belt in the machine?

    Other than cleaning everything with alcohol & replacing the belt(s), what else should I do?

    What will I do with a reel to reel? I remember growing up in the 70's and my Dad had a reel to reel that he loved and would frequently clean. But I don't have a tape colllection. Just the tape that came with this unit that is labeled "a bit of this and a bit of that".
  2. inductor

    inductor Super Member

    the reels are driven thru belts if i remember correct
  3. testwork

    testwork Active Member

    I'll have to take the unit further apart then, I suppose. Thanks!
  4. testwork

    testwork Active Member

    Yep, I found there is at least one more belt, a diamond shaped one in the front compartment.

    Does anyone know which is which when it comes to part numbers? I only need to replace the one in the back compartment.
  5. MoreCowbell

    MoreCowbell Active Member

    There are three belts in the GX-77. One long thin belt runs both capstan flywheels. Two shorter belts, with a square cross section, run each of the reel tables.

    I did a complete overhaul of a GX-77 which wasn't particularly difficult but having the service manual was virtually a necessity. Having a method to keep track of where all of the parts go after you remove them is also a must.

    In order to remove the long thin belt, you have to unscrew one of the short support rods. This is done after unbolting the back frame, that contains the transformer, and laying it down. It's a bit of a puzzle but not that bad.

    Another thing to check is the small spring that is attached to the tape loading pulley in the front of the unit. They apparently have a tendency to break at the point where the spring attaches to the plastic part that holds it. Sometimes this prevents the player from working.

    I purchased the belt kit for my GX-77 from Vintage Electronics.

    Hope this helps.

  6. quadraTOMic

    quadraTOMic Active Member

    I second Vintage Electronics. If you do happen to break one of the springs Cowbell is talking about, and I did, use a ball point pen spring as a replacement. Worked perfect!
  7. testwork

    testwork Active Member

    Thanks, guys! I looked at several places and nobody had a "kit". So I bought the one you linked to above!
    I'll try to take pics of the install if you want.
  8. MoreCowbell

    MoreCowbell Active Member

    In my case, it wasn't the spring that broke, but the attachment on the plastic part that held the spring. I made a new attachment and also made a new spring with less tension as I thought the original was way too strong. The new spring was purchased at a hardware store and was simply cut to the correct length. Here's a link to the thread that I started regarding the loader spring. It also has a few pictures.

    I acquired another GX-77 and it has the same problem. This appears to be a recurring problem with this model.

  9. testwork

    testwork Active Member

    Wow, I got the belts like the very next day after I paid for them. I saved that website to my favs. Thanks.

    You're not kidding about needing the service manual. You wouldn't by any chance have a picture album you could share with me of the teardown, would you?

    I started the teardown but I'm having trouble getting the front faceplate off and the power transformer out of the way.

    Also, I'm not sure of the skinny belt orientation?
    Last edited by a moderator: May 21, 2009
  10. MoreCowbell

    MoreCowbell Active Member

    I'm currently away on a business trip so I'm not able to take more photos. When I get back I'll take a few pics to help. You really do need the service manual. I got mine free off one of those sites that let people upload manuals. I'll see if I can find it and give you the link.

    In order to get the transformer out of the way, you have to cut the zip ties that hold the wire bundles together on the back of the unit. This gives you the slack needed to lay the back frame (with the transformer attached) down.

    I was half serious about it being like a Rubic's cube.

    Alakdan likes this.
  11. testwork

    testwork Active Member

    I assumed you might have already had a bunch of pics taken. No sense in tearing it apart just to take more pictures. :)
    Thanks though!

    The manual link would be appreciated. I'll search for it myself though and post back if I find it!
  12. MoreCowbell

    MoreCowbell Active Member

    Here's three pics illustrating how to gain access to the capstan flywheels. I'm not sure if I remembered everything correctly regarding the rear center support bracket, but it will be fairly obvious once you get started.

    In the pic showing the flywheels, the bar that holds them in place can be seen. It must be removed in order to replace the belt. The main motor is the small can shaped widget in the lower left of the pic. One of it's support rods must also be removed to allow replacement of the belt.

    I sent you a PM. Did you get it?

    Good luck.


    Attached Files:

  13. rockaday

    rockaday New Member

    Dear More Cowbell, I've been reading these threads. I just bought a GX 77 as well. I changed the three belts. Your threads and especially the photos were very helpful and thanks. I will refer to direction of the tape rather than fast forward and rewind because it does both in both directions as it plays both ways. Everthing is fine with the new belts except that it struggles to fast wind with tape going from the right reel to the left. I think this may have something to do with a small mechanism I had to remove to replace the two small belts. There was a spring on the part and a belt of some kind going around the spindle that looked like some sort of braking mechanism. I hope I am describing this ok. With this problem I have do you imagine the problem is with the send reel or the take up reel. I have a feeling it is the send reel that is perhaps 'too tight'. thanks for any input you can give .
  14. KentTeffeteller

    KentTeffeteller Gimpus Stereophilus!

    This deck had very weak motors when new. On a cassette deck, they would have been among the best available. Any tension or other issues only makes that problem worse. This machine was designed for compactness and styling as a priority. The design didn't age well and as the pictures indicate, an intricate thing to service. It's worth love, this model fetches good money to Akai collectors. It is interesting.

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