Battery replacement on Yamaha TX802

My TX802 started behaving like it was broken: strange characters on the display and strange sounds. Not even a factory reset and a following sysex dump helped to remedy this situation. Although there was no „battery low“ warning, I first replaced the 20 years old battery before going on with error search. It turned out, that this was a good decision; everything is fine now and the box is back fully operational. As you can see on the photos, it is fairly straightforward to open the housing and reach both sides of the mainboard. The new battery holder did not fit exactly into the soldering holes, but I found a decent workaround by twisting the pins a bit and underlaying the holder with hot glue.

6 Responses to “Battery replacement on Yamaha TX802”

  1. Luis sagt:

    Funny, I was ready to sell my TX802 because it wasn’t working and decided „why not change the battery“! The symptoms/issues is that playing a performance, each time I would hit a key, it would cycle through each of the 8 parts. In-other-words, if you have „Full Tines“ on the 1st voice and all 8 parts are on (although only part 1 has a voice assigned), playing the keyboard will play part one, pressing keyboard keys again then plays part 2, 3, 4, 5, 6, 7, 8, and then finally plays 1 again!!! Weird. Unfortunately the battery change over was not so easy. Had to take the entire circuit board out and un-solder the original batter (which is permanently affixed to the clip/holder). I then soldered a wire, one each into the Positive and Negative. Haven’t had a chance to find a newe „clip“ so I soldered the wires straight into the new CR3205(? I think that’s what it was) and wrapped it really good not to cause a short. That baby works fine now!!!!!!

  2. LibraryMark sagt:

    Mouser Electronics has the proper battery (with the short leads already attached) for this and other Yamaha units like the DX-7. It is Mouser’s part #614-CR2032FH-MFR, Manufacturer Part #CR2032FH MFR, and can be bought for $1.43 from I was going to go with the socket approach on my Yamaha DMP-11, but could not find one that I felt would fit well enough to suit me. I ordered 3 batteries and had them in four days. Now my DMP-11 is happy again!. But shame on Yamaha for not allowing for an easier way to change these!

    • mike sagt:

      Just found this thread about the dmp-11 battery replacement:
      How did you do it without wiping out the patch library?
      is there a software reset?
      thanks for any help!

  3. Carlos sagt:

    I have just bought a TX 802, and i was thinking in the same solution, next monday i will go for an electrician shop to get a similar solution.

    Thankyou for the photos, well done Guy.