A technical question....

Discussion in 'Amps and Cabs [BG]' started by timbob, Jan 26, 2001.

  1. timbob


    Jan 26, 2001
    I had a question concerning a bass amp i own. Im not very experienced in amp repair and such and i was wondering if anyone could help me out here. Ok... ive been using the amp as sort of a practice/jamming rig. Its a Crate BX-100, solid state, fifteen inch speaker. I was playing it recently (at a fairly high volume, but not full blast) and it blew a fuse. Ever since when i put a fuse in and turn it on it makes a humming noise and immediately blows the fuse. I thought it might be the transformer, but again, i only know basic things about this stuff. Does anybody know what the problem could be, and are there any solutions, short of taking it to the repair man? Any insight would be greatly appreciated.
  2. rickbass

    rickbass Supporting Member

    One reason I use Carvins is because they have circuit breakers, ergo, no blown fuses. But I have owned fuse fryers and it was usually a connection that had come loose or insulation that had been worn or cut due to repeated transport of the head, and it contacts some other metal part, (usually on the lower end gear I've owned). If you feel ok about diving in your head with a solder gun, I say, go for it.

    Me? I'd be at the tech shop.
  3. notduane


    Nov 24, 2000

    Please be VERY careful if you do dive in. From the problem you describe, you're
    probably gonna' start trouble-shootin' the power supply side. There are some
    gnarly, @$$-kickin' voltages flyin' around here! That hum could mean a filter cap
    has gone south. These are usually electrolytic and must be replaced with the correct
    polarity and voltage rating. If you mess that up, there's a possibility of the cap blowin' up.
    About like an M-80.

    If you can, beef-up the power supply: a breaker like Rb1 says, better filtering, etc.
    The p/s is an area that most manufacturers tend to really scrimp on.
  4. Gabu


    Jan 2, 2001
    Woodland Hills, CA
    If you are not... Maybe you shouldn't monkey with it. Asside from the possibility of frying your amp you could really hurt yourself.

    When I was in electronics school in the Navy one of my instructors decided to repair his microwave at home by himself and was electrocuted. He was trained in electronic equipment repairs and still screwed up.

    I would drop the cash and get a pro. (Not a prostitute, they don't know amp repair, silly.)
  5. Don't power it up any more. Take it to a tech before you blow out the speaker. If an output transistor shorted, you are putting about 40VDC across your speaker before the fuse blows.

  6. notduane


    Nov 24, 2000
    Sorry to hear `bout your instructor, gbrooks :( .

    An old instructor of mine told the class this one to keep us from screwin' up...

    He and a buddy were workin' on a high power transmitter. They had the back off and
    power ON so's they could tweak stuff. My instructor's pal dropped a small screw down
    into a big-@$$, air-core coil. After the appropriate cussin', the guy started to
    stick two fingers into the coil's core to retrieve the screw. My teacher's like,
    "Hold on dumb-@$$!!!". Too late. Before he could shut-off power, the guy had his fingers
    all the way in the coil to get that screw. What the guy pulled-out of the coil was a
    couple a' meat-less, bony thangs.