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Fender Blues deluxe reissue. trobleshoot

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  • Fender Blues deluxe reissue. trobleshoot

    Hi.
    Bought myself an blues deluxe reissue for a litle while ago. But since the amp i to loud for me, i ordered this kit:
    eBay - New & used electronics, cars, apparel, collectibles, sporting goods & more at low prices
    this kit contains new volume pots along other thing that should make this amp better.
    But heres my problem.
    After changing out all the components in this kit, i turn the amp on, and there is no sound.
    Im no expert in electronics, so was hoping for some help to trobleshoot.
    I have checked all my work over again, and found som burned traces, that i now have fixed.
    Im afraid that since i power up the amp with bad connections to some parts, i have destoyed something.
    I have sound when plugged into the power amp inn jack, so i guess the problem is in the pre amp area.
    I have signal into the first pre amp tube, but it sems to stop there.
    all i have to measure with is an multimeter.
    What kind of values should i have on the first pre amp tube, i have 360 V going in there, should i have so much?

  • #2
    Well, you certainly have your work cutout for you.
    I would check, check & double check everything that you have done to the amp.
    There are test points on the schematic.
    Check them all.
    The first preamp tube input voltage is marked "X" on the schematic.
    It should be around 345Vdc.
    You want to make sure that you did not break any of the ribbon cable connections that go board to board.
    A good way to check the preamp tubes is to measure the Vdc at the plate pin & the cathode pin.
    You want to see a voltage drop across the plate resistor & a smallish voltage on the cathode.
    Attached Files

    Comment


    • #3
      Originally posted by Jazz P Bass View Post
      Well, you certainly have your work cutout for you.
      I would check, check & double check everything that you have done to the amp.
      There are test points on the schematic.
      Check them all.
      The first preamp tube input voltage is marked "X" on the schematic.
      It should be around 345Vdc.
      You want to make sure that you did not break any of the ribbon cable connections that go board to board.
      A good way to check the preamp tubes is to measure the Vdc at the plate pin & the cathode pin.
      You want to see a voltage drop across the plate resistor & a smallish voltage on the cathode.

      I have check and double checked many times, the ribbon cables are ok, have measured all off them from board to board.
      im norwegian so im sorry that i dont understand all. what is the plate pin, and what is the cathode pin??
      i have also checked that i have signal from the input jack down the coax cable into the pre amp tube, but shall this signal continue out from the coax cable on the other side?

      Comment


      • #4
        12AX7 pinout.
        1/2 of tube:
        The plate is pin 1/ cathode pin 3
        The plate is pin 6/ cathode pin 8
        Attached Files

        Comment


        • #5
          I just spent 2 hours of bench time fixing a home modified Deville. Wrong part values, broken traces, you name it. The really hard part is trying to find all of the places that had been worked on before.

          As JPB suggested, double check all of your earlier work. Look for lost continuity on any of the pc traces that you worked on. They may look ok, but you need to test them with your meter to be certain that they are still making connections.

          Comment


          • #6
            Originally posted by Jazz P Bass View Post
            12AX7 pinout.
            1/2 of tube:
            The plate is pin 1/ cathode pin 3
            The plate is pin 6/ cathode pin 8
            pin 1 gives 345 volt
            pin 3 gives 5 volts
            pin 6 gives 235 volts
            pin 8 gives 2 volts

            Comment


            • #7
              Originally posted by 52 Bill View Post
              I just spent 2 hours of bench time fixing a home modified Deville. Wrong part values, broken traces, you name it. The really hard part is trying to find all of the places that had been worked on before.

              As JPB suggested, double check all of your earlier work. Look for lost continuity on any of the pc traces that you worked on. They may look ok, but you need to test them with your meter to be certain that they are still making connections.
              i have double checked this many times, but will check it again, just for sure.

              Comment


              • #8
                My calculations tell me there should be around 260VDC at the V1 plates (going by the cathode voltages).
                So your voltages at pin 1 and 3 seem to indicate a problem with V1A. Try wiggling it around in its socket, try a different 12AX7 there. Other suspects would be the solder at the tube socket, the plate and cathode resistors (R4 & R5), or the ribbon cable connections PW1A-1, PW1B-1, PW1A-3, PW1B-3.
                Were R4 or R5 involved in any of the mods?
                Originally posted by Enzo
                I have a sign in my shop that says, "Never think up reasons not to check something."


                Comment


                • #9
                  Originally posted by g-one View Post
                  My calculations tell me there should be around 260VDC at the V1 plates (going by the cathode voltages).
                  So your voltages at pin 1 and 3 seem to indicate a problem with V1A. Try wiggling it around in its socket, try a different 12AX7 there. Other suspects would be the solder at the tube socket, the plate and cathode resistors (R4 & R5), or the ribbon cable connections PW1A-1, PW1B-1, PW1A-3, PW1B-3.
                  Were R4 or R5 involved in any of the mods?
                  bad connection to the ground end of R5 and C11. now i got sound.
                  After fixing this the volt on the pin 1 was around 250 volt. Thank you all

                  Comment

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