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  1. K

    SX-3800 with dead display and no sound

    Just wanted to close the loop. The Q209 was indeed bad, new transistor is in and works like a champ. Thanks!
  2. K

    SX-3800 with dead display and no sound

    Good to know about the 2sk34's, I thought the 2n4401 was a substitute for the 2sc1318 in the power board on the sx-850 but I may be getting things crossed by now. It is amazing how lost you can get sifting through the forums, truly a wealth of knowledge! I will be sure to have several of the...
  3. K

    SX-3800 with dead display and no sound

    Understood, I will get the correct parts order going now. I have added all the components from your power supply board parts list + the new plastic transistor sockets + Suggested replacements for Power amp (GWH 139) board: GWH-139: Q107: 2SA750 (2SA726S): 512-KSA992FBU (common failure: causes...
  4. K

    SX-3800 with dead display and no sound

    By chance could someone take a look at my attached comparison on the transistors? I would like to try my BD139 for the position Q209 (2SD313) (512-KSC2073TU). I believe I can still attach the stock heat sink but only 300mA flowing (per the drawing) I would think the temps will be ok? I would...
  5. K

    SX-3800 with dead display and no sound

    Based on the testing results I suspect the Q209 (2SD313) is bad, I see the equivalent recommended is the Mouser 512-KSC2073TU, when I checked my spares box I did find some BD139's but was hesitant use it as a substitute based on the differences I found with the Mouser comparison. According to...
  6. K

    SX-3800 with dead display and no sound

    I did find some BD139 transistors. They are also 1.5A, NPN, but are only 80V, and .5v off on saturation voltage. They are also generics. Do you think the .5V increase on the output would matter? I could add a diode to the output to get a little closer and I don't think I would ever exceed the...
  7. K

    SX-3800 with dead display and no sound

    Thanks Mark! I was also wondering if I should have revived this old post. I will remember that next time. Mostly in this case I was hoping to group like problems together, thought it might help others down the road not have to look in multiple locations. I took a closer look and tested the...
  8. K

    SX-3800 with dead display and no sound

    Hi there, first off this forum has been fantastic in reviving my old sx-3800. It also suffered from the cracking power transistor bases causing the left channel to clip. Now that I know what that problem was and how to fix it I have moved on to the next problem. I am getting near 0volts on the...
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