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SVT-4 shutting off...

Discussion in 'Amps and Cabs [BG]' started by GrandMarkie, Jan 6, 2005.


  1. GrandMarkie

    GrandMarkie

    Feb 7, 2004
    Waltham, MA
    It's been happening for the past few weeks now. After about a half hour, the amp shuts off and the fan kicks into super high gear...then the amp turns back on and the fan goes back to normal and repeats. What's the deal? I haven't changed any settings or volume. It's 10 months old.
     
  2. Jerrold Tiers

    Jerrold Tiers

    Nov 14, 2003
    St Louis
    Dunno what "the deal" is, but my guess is it is heat related, and probably something simple.

    The fan automatically goes to high speed whenever there is a "fault" condition. Overtemp is a "fault". But since it is working until that, nothing very bad can be wrong.

    Do you have it in a rack? If so, is the airflow clear, particularly the exit vent?

    If there are no obvious airflow issues, or that doesn't resolve it, sounds like you are well within the 5 year warranty, take us up on it.
     
  3. GrandMarkie

    GrandMarkie

    Feb 7, 2004
    Waltham, MA
    It's currently in a rack with about 2-3 inches of clearance on each side and about 1 inch of clearance on the top and bottom.

    I'll try playing with the amp out of the case to see if that solves anything. But if it is heat related, why would this happen all of a sudden when I have been doing the same thing for 10 months? Has the heat caught up with the amp and caused damage?

    Thanks for the help AI.
     
  4. ESP-LTD

    ESP-LTD

    Sep 9, 2001
    Idaho
    You might make sure your cables are OK. If one is shorted the amp could be shutting down in self-defense and coming back for more after it cools off. I had an SVT-400T that did that.
     
  5. GrandMarkie

    GrandMarkie

    Feb 7, 2004
    Waltham, MA
    Well now it seems it may be my cab (ampeg 8x10)

    Today, I used the output on the SVT-4 to our mixer and out to our PA system. The amp was fine this way, but as soon as I hooked it directly to my cab, the amp turned off. BTW, I tried both mono bridged and stereo (2 different cables) and it did the same thing with both, so it seems its not the cables.

    What could be wrong with the cab, it seems not much can go wrong with it? Any other things I can do to test my amp/cab? Maybe it's the outputs on my amp?
     
  6. notanaggie

    notanaggie Guest

    Sep 30, 2003
    Hmmmmm..... That may not be a real test.....if you just used the line out, you probably didn't have anything connected to the power amp. So you were not using the power amp, right? That's an SS amp, right? So that would mean no stress on power amp.

    If you were not using the power amp, then it would not overheat, unless there were some real problem with it, like it was overbiased, etc.

    So the question is does it shut off if you use some OTHER speaker cab that isn't that one?

    BTW, it has a fan in it.....is the fan running normally, or just when it shuts off? Do you feel warm air exiting from the vents normally?
     
  7. GrandMarkie

    GrandMarkie

    Feb 7, 2004
    Waltham, MA
    I called an ampeg technician, they say its a thermal problem.

    The fan runs normal when its working, then for the 10 seconds it cuts out, the fan goes into super high gear. If I play my bass rather hard, it cuts out faster. Some type of overload is going on.

    The technician told me it takes a few weeks to get fixed... I have 3 gigs within the next few weeks :(
     
  8. Jerrold Tiers

    Jerrold Tiers

    Nov 14, 2003
    St Louis
    You should be able to get it serviced locally, I would think....where are you located?

    Local service is usually much faster than sending it back to factory service.

    Since the amp works normally, aside from shutting off, it could even be that the temperature sensor has developed a problem. Might be simple.
     
  9. GrandMarkie

    GrandMarkie

    Feb 7, 2004
    Waltham, MA
    I brought it in to a local ampeg technician today. Hopefully it doesn't take too long, i'll post what the problem is once I found out. Thanks for everyone's help.