Forum Top Banner Ad


Ebay Classic organs



No announcement yet.

Galanti Praeludium II

This topic is closed.
  • Filter
  • Time
  • Show
Clear All
new posts

  • Galanti Praeludium II

    Wondering where the problem might lie with this issue. When I first turn on the organ, the Swell Gambe 8' is very soft, almost silent but sounds on all keys. When the 2 2/3' is played (in the swell) it makes a little blurp and then goes silent. After playing the organ for about 20 minutes or so (with other stops) both of these stops begin to work perfectly. If the organ is turned off and then turned back on again all is well. It just happens when the organ has not been used for a while.

  • #2

    The 2 stops you mention come from the same digital sound generator - from tone gen. board #1, IC #2.

    If you don't mind doing a little work yourself, try levering the M-114, the associated E-prom, and the masked ROM ( the IC on the top corner with GEM and INTEL written on them. Then re-seat them.

    Also, you could try pulling the Tone Generator board and re-seating it. You could also swap M-114 ICs and see if the problem moves.

    Beyond that, could be a bad capacitor on the M-114 chip, bad connection at the other board or mixer board.

    The boards and layout of parts on the board is not that complex, but, without an extender card, it is hard to test the board in situ. At least we know that nothing has blown up.

    Remember to be careful when handling circuit boards. Try to avoid static discharge as much as possible. Those organs also had problems with poor solder connections. You may want to re-head any that look suspect.

    Whenever pulling out circuit boards or re-seating them, do so with the organ turned off.



    • #3
      Can you explain "levering"


      • #4
        Those DIP IC's, it is easy to bend the end pins back if you just pull them out. You take a bent tip pick, you stick under one end to pry it up a little, then raise the other end a little, then raise it some more by levering back more, then back to the first end to lever it up until it is even, then a third iteration and it finally releases.
        you can do the same thing by using a wide, thin, screwdriver blade (ground down probably from a fat one) and twisting it under each end to lift the ends evenly and no damage the end leads.
        The pro way is to buy a Pamona DIP clip of the appropriate size, clip it over the DIP package and pull straight up. But the 24 pin one is about $30 last time I looked. A DIP clip does enable you to use a scope probe or grabber clip on the pins and check the signal, without shorting across as likely as the flat DIP package pins that are closer together and shorter.
        Be sure to figure out which end is pin 1 before you pull up. A dot next to it or a cut in the package on that end are the signs.
        Be sure to not insert the package one pin off when putting back in. Use reading glasses if necessary (not until age 58 for me), and a lot of light.
        city Hammond H-182 organ (2 ea),A100,10-82 TC, Wurlitzer 4500, Schober Recital Organ, Steinway 40" console , Sohmer 39" pianos, Ensoniq EPS, ; country Hammond H112


        • #5
          Amen to the glasses and lots of light!
          *** Please post your questions about technical service or repair matters ON THE FORUM. Do not send your questions to me or another member by private message. Information shared is for the benefit of the entire organ community, but other folks will not be helped by information we exchange in private messages!


          • #6
            Sounds like something for the professional - I am an organist, not a computer tech! :)
            Thanks for the input.


            • #7
              I may attempt to remove the slave #1 and reseat it. What is the name of the product that cleans contacts and improves conduction? I have seen it on the forum but cannot recall the thread.


              • #8
                I have been using the organ now for a few weeks. The problem with those two stops only occurs when the organ is "cold." If I play the organ for 20 minutes or so, then use them the problem does not occur. Seems to me this is a "thermal" problem - they are OK after the organ is warmed up (I assume, as with a computer, that some warming of the circuit boards occur) Would this narrow the search for a solution?