Recent content by drbacklash

  1. drbacklash

    Marantz 2285b repair in NC

    Both AM and FM reception went out on my 2285b recently (not weak but nonexistent) and I am looking for someone in NC or northern SC to repair it. I live on the east coast of NC between Wilmington and Myrtle Beach. Any referrals? The entire unit was professionally restored about 5 years ago. I...
  2. drbacklash

    Marantz 2285b repair in NC

    I have a beautiful 2285b that was working fine until it wasn't. I'm getting nothing (no signal, no sound, no static) when I select FM so the tuner is suspect. I took the cover off to see if there was something obvious but nada. Everything else works fine except the tuner. My options are to...
  3. drbacklash

    Eleven GX Woes

    I pulled this 50 lb receiver out today to work into my rotation. No problem last time I had it on (2 years). Lights on, relay click and no sound. Flipped the M.A.C. lever and call the fire dept! Opened it up and R48 330 0hm resistor on the right channel side is cooked with smoke damage all...
  4. drbacklash

    AU 717 problems

    I am very careful when I replace components. I draw diagrams, make notes and even tie various colors of knitting yarn on wires to make sure I don't do exactly what I did this time. I did it in stages, over time so I may have been tired or it may have been late at night. Anyway it happened and...
  5. drbacklash

    AU 717 problems

    Many thanks to Lee for being so smart and patient and willing to fix this unit for me. And thanks to Hyperion for his interest in saving this nice piece of gear. You can never be too careful in documenting your own repair work!
  6. drbacklash

    6060 F-2648

    I have a 6060 that has a popping in one channel. The power board is a F-2701 but my service manual shows the F-2648. The manual is for both the 5050 and 6060 so I expect some boarders interchanged between the two units. Where can I find data for the 2701?
  7. drbacklash

    AU 717 problems

    I have now completed replacing all questionable resistors on both driver boards including the Zener Diodes. This work did not correct the problem. The unit still comes out of protection but the DC offset cannot be adjusted. On both left and right channels the readings start at 0 mv and...
  8. drbacklash

    AU 717 problems

    Thanks John, useful information.
  9. drbacklash

    AU 717 problems

    I checked all resistors and diodes again and found some I will replace. I know that you sometimes have to pull a component from the board to get an accurate reading but I figure that if you have to pull it you might as well replace it. Any resistor out by more than 5% gets a permanent...
  10. drbacklash

    AU 717 problems

    Ok, my plan of action is to recheck all resistor values on the driver boards, checks replaced diodes, and then transistors. I sometimes read where the value of components were listed incorrectly in the service manuals. Are there any known errors in the 717 manual?
  11. drbacklash

    AU 717 problems

    Here are the results of the tests: F-2722 right channel driver All connections to F-2721 disabled. With Molex connected, ranges from about 250-280 mv but will not settle. With Molex not connected, increases from 0 to 400 mv and then recycles. F-2721 left channel driver With Molex connected, 0...
  12. drbacklash

    AU 717 problems

    Understood.
  13. drbacklash

    AU 717 problems

    A point of clarification: Looking at the driver board, moving down from the Molex, the pins are numbered thusly: F2721 02 white 03. White 08. Orange 13. Purple 12. Yellow 04. Gray F2722 02. Black 03. Black 08. Brown 13. Green 12. Red 04. Blue So pins 3 and 4 would match up to pins 08 and 13...
  14. drbacklash

    AU 717 problems

    Ok, got it.
  15. drbacklash

    AU 717 problems

    Not familiar with the term output emitter network. Are you looking for voltages at R46 or somewhere else?
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