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Help! My amp won't work!

Discussion in 'Amps and Cabs [BG]' started by yoshi, May 13, 2004.


  1. yoshi

    yoshi

    Jul 12, 2002
    England, London
    Hi all. About an hour ago I went to jam on my bass and to my horror the amp won't turn on. I've tried:

    Replacing the fuse
    Using a different power chord
    Plugging in to a different socket

    ..all to no avail.

    It was working totally fine last night and there has not been any incident with it since - I havn't even turned it on :/

    It's a Trace Elliot 300W GP7SM (combo). I've had it about 2 years now and this is the only trouble I've ever had..

    I've looked in my manual that I got with it but can't find the section titled 'HELP! IT WOT WORK!' :p

    Cheers!
     
  2. tkarter

    tkarter

    Jan 1, 2003
    kansas
    Make sure there is no ground fault interrupter in the electrical outlet that has tripped. Sounds more like what would be going on to me than the amp at fault.

    tk
     
  3. hes probably right. I did the same thing with my Mesa 400+ a while ago in my garage, and I can understand how you feel, it really freaked me out.
     
  4. Eric Moesle

    Eric Moesle Supporting Member

    Sep 21, 2001
    Columbus OH
    Sometimes there is a secondary fuse inside the amp casing, mounted right on the circuitboard. If you feel comfortable opening the amp up to check, you might want to do so. Be careful to make sure the amp is unplugged when you do.
     
  5. yoshi

    yoshi

    Jul 12, 2002
    England, London
    I'm not sure if I'm getting your point but I did try plugging into a different socket - one that definatly worked as my TV was running off it.

    I've had the circuitry out before - a looong time back so I'll go try it out again and keep an eye out for a secondary fuse.
     
  6. This exact same situation happened to me before, and it is the ground fault interrupter thingy he tripped, not the amp, i thought somethign was wrong wiht my amp, but there wasnt.
     
  7. yoshi

    yoshi

    Jul 12, 2002
    England, London
    Hi again, I slid the circuitry board out and had a look around but could not find a fuse of any kind.. :'O(

    WOuld someone please explain what a 'ground fault interrupter' is as I've no clue to be honest so can't check it :/

    I think this calls for a trip to the local music store..
     
  8. tkarter

    tkarter

    Jan 1, 2003
    kansas
    It is usually a square button in between the plugs in the outlet. I see you are not in the States so I am not sure of how that would be applied in your electrical standards.

    Is the power cord hard wired into the amp or is it replacable like most computer power cords are? I would try a different one if it were that way.

    tk
     
  9. yoshi

    yoshi

    Jul 12, 2002
    England, London
    The cables fine - I've tried using my brothers cable aswell as checking the validity of mine by running his amp with it. nay luck.

    I'm really lost without it now...why me :'O( why not some punk who plays every 8weeks? Why not feildy?

    :spit: :bawl:

    I'll take it to a local shop tomorow and see what they reckon, cheers anyway though :)
     
  10. Paul A

    Paul A

    Dec 13, 1999
    Hertfordshire U.K!
    Hi Yoshi,
    There ARE 2 more fuses.
    They are actually on the circuit board, trouble is... they DON'T LOOK like fuses!
    They are tiny "pico" type fuses about 2mm by 4mm, grey in colour and socketed.
    They are located at the top edge area near the wiring loom connectors.
    Best way to find them is to gently pull on each component that looks as I've described ... the ones that come out are the fuses!
    They are very difficult to come by (Maplin don't do them) you can get them from Cricklewood Electronics though.
    There will be a reason for why they've blown and its usually the pre amp valve gone faulty - so you may need to replace that.
    Other causes may be - there is a pair of rectifier diodes near the edge connectors for the wiring loom - these sometimes die (especially if the amp's plugged in and you get a mains surge).
    Or the mains transformer may have gone faulty.
    If you want to p.m. me your address I have a load of these fuses in my spares box I'll send you a few.
     
  11. yoshi

    yoshi

    Jul 12, 2002
    England, London
    Thanks a lot for the information as well as the offer - I greatly appreciate both :)

    However, I've looked again and couldn't see anything matching the bill, not even barely resembling it :/ My amp isn't a vavle amp, though, which could be why they aren't there.

    I'm taking it to the local shop today/tomorow for him to have a look at. I'll pass on all this information that everyones put forward.

    Thanks once again.
     
  12. Paul A

    Paul A

    Dec 13, 1999
    Hertfordshire U.K!
    Hmmm .... most Trace's I've worked on a have a valve pre amp section.... I guess not with this one.
    Try speaking (or emailing) this guy:

    www.gmaudio.co.uk

    He's the Godfather of all things Trace Elliot, if he doesn't know , no one does!

    :)
     
  13. yoshi

    yoshi

    Jul 12, 2002
    England, London
    Hi again, cheers for that link - I've just emailed him now :) Strangely enough, I emailed Trace Elliot on thursday and got the same refferal in an email last night.

    I do actually have the amp booked in (not formally) at the local music shop on wednesday but I'll see what the guy at gmaudio has to say first :)

    Sorry it's took so long to reply, I havn't been on all weekend.
     
  14. Yoshi,

    You've done about all a non tech person should do. If you keep nosing around inside the thing, sooner or later you're really gonna screw it up. Take it to a good tech. I know these things because I'm old and I've screw up a few things and should have known better. It just isn't worth it.
     
  15. Paul A

    Paul A

    Dec 13, 1999
    Hertfordshire U.K!

    Nope.... disagree with that entireley, this is exactly how you learn how things work (assuming you have a little common sense).
    Example:
    Replace 2 blown power transistors - Shop cost about £60 +

    Do it myself - cost about £5 (or less!)

    :)
     

  16. Turning it on and watching those new power transistors fry immediately because you didn't replace the leaky driver transistor that caused them to fail in the first place - Priceless! :D

    I kid, I kid. I'm all for learning how to fix your own stuff, but everyone needs to know their limits. If the guy doesn't even have a voltmeter or even know what a capacitor does, he's probably in for a very frustrating task.

    Chris
     
  17. Paul A

    Paul A

    Dec 13, 1999
    Hertfordshire U.K!
    There are........... NO LIMITS! :ninja: :D
     
  18. Sounds like you got lucky because without proper trouble shooting techniques and tools, you're just stabbing in the dark and replacing parts. Common sense tells me to find a professional.
     
  19. Paul A

    Paul A

    Dec 13, 1999
    Hertfordshire U.K!
    No, I KNOW what I'm doing, (I repair and service amps for Johnny Turnbull of The Blockheads and Bob Geldof's band as well as repairing and making effect units).
    Power Transistors, as you may well know,can (and often) pack up because of the bad quality cheapy units that manufacturers use.
    An awful lot of times it's just the power transistors and nothing else.
    None of the repairs that I have done,probably upwards of a couple of hundred amps of different types,tube and solid state have yet failed....... (yet!).
    I don't "stab in the dark" I do use "proper" troubleshooting techniques.
    But ...I would say 90% of what I've learnt is by "having a go"!
    :bag:
     
  20. yoshi

    yoshi

    Jul 12, 2002
    England, London
    Sorry to interrupt the argument ;)

    My amp's working fine now! I took it to the repair shop and it turned out that it was blown fuse - only the fuse was located within the power switch, right where the chord plugs in. Who'd have guessed that the fuse icon on it represented an internal fuse? ;)

    Thanks a lot for all the help though!