Velodyne sub woofer blowing fuse...HELP!

Discussion in 'Amps and Cabs [BG]' started by iceboxbass, Dec 7, 2015.

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  1. iceboxbass

    iceboxbass Living the Dream!

    Feb 22, 2010
    Michigan
    Hi!

    I have a Velodyne CT-120 that I use in my home entertainment system. The issue that I'm having is that it keeps blowing its fuse on the circuit board, 2amp fuse. I've taken the circuit board out of the sub cab, looked around for anything obvious like swollen/cracked components, burnt or scorched spots, shorted wires/solder bleed over, cracked solder joints, NOTHING. But I did find some white powdery residue on one side of a black wire connected to rear circuit board that's in front of the transformer and there are a couple of condensers in that area on same board as well. Not really sure what the white powdery substance is, also there is some brownish substance in a couple of places on the rear board closes to transformer on a cap. I installed a brand new fuse last night and while I still had the circuit board/back panel removed away from the cab, I plugged in the power cord, turned power switch on and the fuse blew right away. If you have any insight that you could share I'd sure appreciate it so very much. Thank you!
     

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  2. Shorted output section probably. Blown output transistor(s). You won't be able to fix it without a schematic, tools, and certain knowledge. Off to the tech!
     
    Last edited: Dec 7, 2015
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  3. cfsporn

    cfsporn

    Aug 20, 2011
    New York City
    Um... Why are you using a Velodyne SW with your bass rig?
     
  4. iceboxbass

    iceboxbass Living the Dream!

    Feb 22, 2010
    Michigan
    Thank you David for your insight. I'm handy with electronics and soldering but I'm having trouble finding a schematic for this. I might just contact Velodyne to see if I can buy another power circuit for it. This one is outdated but perhaps one of the new power circuits will work with this sub. It's worth a try.
     
  5. iceboxbass

    iceboxbass Living the Dream!

    Feb 22, 2010
    Michigan
    I'm not...I'm using it in my "Home Theatre" system. Though this is a bass forum I was hoping that there's an expert in here that can help out.
     
  6. cfsporn

    cfsporn

    Aug 20, 2011
    New York City
    Fair enough. I was worried you tried to use it as a full range bass cab.


    Cary on!:thumbsup:
     
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  7. cfsporn

    cfsporn

    Aug 20, 2011
    New York City
    This may help. CT120AmpBoard.JPG
     
  8. Maybe, but I doubt it. Sorry to be a wet blanket but honestly, if you can't troubleshoot it at board level, it's probably not worth persuing. You'd be surprised how tough it can be. You gotta really know your $∆!t.
     
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  9. iceboxbass

    iceboxbass Living the Dream!

    Feb 22, 2010
    Michigan
    I took electronics in HS and then trained in electronics troubleshooting/repairing in the USAF 26 yrs, but I need schematics for this. I can test component by component but I'm really not wanting to take that kind of time (hours/days unless I get lucky) repairing this sub. Just hoping someone else ran into this same kind of thing with Velodyne subs. Might be time to upgrade to a 15"! Find a great Christmas sale! Or buy a floor demo model for less $$$. :)
     
  10. cfsporn

    cfsporn

    Aug 20, 2011
    New York City
    See my above post.
     
  11. OK, you have the knowledge and maybe the tools. I'd suggested posting on some techy HiFi site? Maybe try Velodyne themselves? You'd probably have better luck.
     
  12. iceboxbass

    iceboxbass Living the Dream!

    Feb 22, 2010
    Michigan
    Very NICE:thumbsup: This one is for the ct-120? I'm not seeing the model on it...
     
  13. iceboxbass

    iceboxbass Living the Dream!

    Feb 22, 2010
    Michigan
    Yeah, I posted on a forum called dyiAudio.com. Waiting on mod to approve my post...sent Velodyne tech to respond to my question also. But hey, one cannot get too much help right?
     
  14. cfsporn

    cfsporn

    Aug 20, 2011
    New York City
    That is what the Google Machine told me!
     
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  15. True dat. I'd go ahead and CALL Velodyne.... Email gets lost/forgotten. They probably get a lot.
     
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  16. iceboxbass

    iceboxbass Living the Dream!

    Feb 22, 2010
    Michigan
    Great ideas David:thumbsup: Also thank you cfsporn for the schematic :thumbsup: I just did a Google search and actually found a Velodyne support/repair forum I'm going to next. And a repair on YouTube. Thanks guys, your great!:cool::)
     
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  17. cfsporn

    cfsporn

    Aug 20, 2011
    New York City
    7You're welcome. I was an AV dork before I knew the difference between a guitar and a bass guitar, so I gotta rep for my Hi-Fi homies whenever I can.:roflmao:

    Anyway, back to the board. Does any part of it smell weird? Any singe marks on the PCB? Those could be your first clue to finding the busted component. Failing that, you may want to check the power cord. If it has a short, then all bets are off.

    Finally, a huge +1 to calling the company. I know emails are easier in every sense of the word, BUT THEY DON'T GET **** DONE LIKE A GOOD PHONE CALL! Take it from someone with horrible social anxiety and dreads talking on the phone; calls have their place, this is one. Velodyne's number is +1-408-465-2800. They're hours are 7:00AM to 4:30PM PST. Call them!
     
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  18. iceboxbass

    iceboxbass Living the Dream!

    Feb 22, 2010
    Michigan
    I didn't smell anything out of the ordinary but a short in the pwr cord is a great idea. Tomorrow I'll get my multimeter out and do a continuity test on it. Sometimes it's the most obvious that we don't see, even though I try to keep that foremost in my mind when troubleshooting. Thanks for the phone #, I've been on their page as well. Yeah I tend to tire going thru phone trees waiting and waiting and waiting...but sometimes it's the best avenue. Cheers!
     
  19. Shorted power cord would blow your mains supply, not your amp fuse.
     
  20. iceboxbass

    iceboxbass Living the Dream!

    Feb 22, 2010
    Michigan
    The pwr cord goes thru the fuse board first. See photo.