I've got a pro power three in need of repair. I realize this amp is not worth much, but cosmetically it's mint, and frankly I think it sounds pretty good cranking out tunes in my basement shop system. Still plays great, but the cooling fan no longer works. Nothing wrong with the fan, no power at the connection point on the board. A Google search returns pretty much zero in terms of repair options. Anyone have experience with repair shops on the east coast that might be up for it?


  • VR3
    VR3 Posts: 26,912
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  • treitz3
    treitz3 Posts: 16,688
    Are you near Atlanta?

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  • DaveHo
    DaveHo Posts: 3,378
    SE PA, Reading to be specific. I'm leaning toward EBC electronics in NJ. Though they don't, and neither does anybody else, list Soundcraftsmen as one of the brands they service.
  • audioluvr
    audioluvr Posts: 4,803
    Any self respecting electronics repair facility should work on vintage electronics. Not for free of course
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  • mhardy6647
    mhardy6647 Posts: 31,251
    edited January 28
    Seems like the potential (no pun intended!) issues, if not the fan itself, would be the power supply to the fan or (if there is one) a thermostatic switch that turns it on and off. I would be surprised if the power supplied to the fan is unique to it; i.e., loss of power to the fan might reasonably be expected ;) to have other effects. IF (and that's a big if, since I don't know) there's a thermostat (or even just a relay) upstream of the fan -- it should be easy to diagnose and easy to repair.

    Is the fan AC or DC powered? @DaveHo When you say there's no power to it, did you check for AC or DC (or both)?

    I don't know this model Soundcraftsmen, but I'll see if I can find a schematic. :)

  • mhardy6647
    mhardy6647 Posts: 31,251
    edited January 28
    Whoop. Looks like the fan runs straight off the AC mains (EDIT: umm, or maybe it's from that fullwave bridge on the neutral leg?! derp :p ). Not much to go wrong; maybe the power connector for the fan (EDIT: or the bridge rectifier, the capacitor or the resistor in that little P/S... although, again, I would expect issues there to have "pleiotropic" effects in the amplifier!).

    EDIT^2: Pretty sure the fan's running from the AC mains. The 240V wiring inset on the schematic is what's confusing me. Well, at any rate, that's my story and I am sticking to it! :p

    jhd6e5xbwd9g.png Power Schematics.pdf

    Post edited by mhardy6647 on
  • newbie308
    newbie308 Posts: 498
    You can try Mort's in Levittown PA. That would be about a 1 hour drive for you. BTW I'm in the Reading PA area, too. Shillington.

    Mort's TV & Video Inc.
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  • Gardenstater
    Gardenstater Posts: 3,490
    I gave the schematic a scan and noticed there is a fuse (3A, 250V?). That is something to check, if it hasn't been mentioned.
    George / NJ

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  • mhardy6647
    mhardy6647 Posts: 31,251
    edited January 28
    I think that's the mains fuse (although 3A seems a bit low for a stereo power amp of any reasonable output). If so, though: were it popped, whole shebang'd be muerto.
  • DaveHo
    DaveHo Posts: 3,378
    edited January 29
    Thanks for the suggestions. Let me pop the cover again and recheck the connection point on the board for power. Don't recall if I checked for both AC & DC. It very well may be the fan. When I didn't get any power at the board, I assumed it was not...
  • mhardy6647
    mhardy6647 Posts: 31,251
    edited January 30
    If you checked for DC and the connection is AC, you'd (edit: probably) see zero V. If you checked for DC and it's AC, you'd probably see zero V, too.
    Although I agree the fan should be more or less immortal. :)
    Post edited by mhardy6647 on