Announcement

Collapse
No announcement yet.

Echoplex EP-3 Troubleshooting no audio

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Echoplex EP-3 Troubleshooting no audio

    Hoping I can find some help and guidance as this is the first echoplex that I’ve taken apart and decided to work on. There are two main concerns of mine that I haven’t been able to get a perfect answer on yet. Those can be found below.

    This echoplex powers on and the motor runs REALLY smooth. The issue is that there’s no output sound whatsoever. I used an audio probe and found that my sound does after the first transistor in the preamp circuit.

    There is a ground wire that was hanging below the unit that apparently wasn’t connected to anything. I need guidance on where this ground cable screws onto. I noticed that the fan and casing of the motor weren’t grounded so grounded it to that as I thought that I could see it like this in other photos.

    After running the unit for around 25 minutes while checking voltages, the .1mfd capacitor located underneath the power supply board burned up. Is this because I grounded it to the motor casing or because this unit has definitely not been on for that long in a million years? Regardless I’m looking for all of the guidance that I can get as this is the first one of these that I’ve worked on. There’s also a very Loud ground hum that comes through amplifiers when the unit is plugged into it. This hum does not come from it being turned on, it’s present even when the unit is off and just plugged into the wall. SEND HELP!!!!

  • #2
    I've got the identical issue that you have. A buddy just got his a few days ago. When I took it apart, there was a black, 2", wire lying in the bottom of the cabinet. I have no idea where it came from or what it connected to. I connected my scope to it with a 1KHZ signal get a signal up to the point of the 220K resistor on the Echo/Sustain pot, but no signal afterwards even though the electrical connection to the output jack is fine. What was your black wire connected to?

    Comment


    • #3
      I found that the 35uf 25VDC cap by the Q5 transistor was shorted. I replaced it, and got it working.

      Comment

      Working...
      X