Oh dear. Blew my amp. Help!

Discussion in 'Amps & Cabs' started by jetlag, Aug 23, 2008.

  1. jetlag

    jetlag Member

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    :cry:

    Not fun times.
    Looks like I've gone done my amp in.
    Not being much of a techno geek with amps as I am pedals, I don't know where to start.

    I never usually use my head/cab for practice, but we had a nice hall today so thought why not.
    Amp seemed fine, if running slightly hotter than usual (the room was warm though).
    During our last song we were practicing, amp just died.
    No lights on valves weren't lit. Nothing.

    AND a godawful stink.
    And it was HOT. As in, burning-your-fingers-touching-it kinda hot.
    Panic panic panic.

    I should point out here, I have a Marshall DSL100 head into a 1936 2x12.
    Usually the red light/power on button has a feint red light when plugged in, full red light when it's on. The full power light wasn't on, but the feint light was.

    Absolutely reeking of sommat burning.
    Still is!

    Basically, I want to try to diagnose this badboy before I take it to a shop monday, so i'll have a rough idea of what it's going to cost.

    Couldn't have happened at a worse time to be honest - no money to fix it (gonna hve to borrow off family or something) and I've got 3 bloody gigs this week. >:(

    Anyway.
    I'm going to take the back off now and have a peek.
    I'm pretty sure it wasn't a fuse as it would have cut power and not smelled like burning plastic.
    I'm pretty sure it's not the tubes, since the amp would have just cut out, but the power light should have stayed on, surely? I guess they might be fried now though...

    So I'm thinking maybe it's one of the transformers gone?

    Like I said, I'm no amp expert so any advice would be greatful!

    I hate **** breaking.
    On a good note, I got my whammy working...? ;D
     
  2. 1Way

    1Way Active Member

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    Sorry to hear about your problem. Wishing you the best for it’s healthy return.

    First order of business is safety. Most amps store enough residual current to potentially kill someone. That's no joke, so no matter what, be very careful even after you unplug the amp!

    I'd say you should be looking for noticeable damage to things like insulation, either for wire leads or like you mentioned, a blown tranny.

    Perhaps one of your speaker connections/chords developed a bad connection which in turn altered the normal current flow and a poor ohms mismatch.

    If you can't tell by examining the amp the way it is, you may want to 'carefully' remove the chassis to take a look inside. I hate to say it, and I'm no amp tech, but it sorta sounds like you may have catastrophic problems like a blown transformer or something similar. I'd also pull every tube to see if there is any arching on the sockets or flair residue on the tubes somewhere.

    You could call an amp tech to see what they suggest for you to try to examine on your own.

    Remember, if you lift out the amp's guts, be very careful not to touch the electronic circuit or exposed parts for risk of a serious voltage discharge. I've read that you can get a special grounding device that I believe utilizes a capacitor/resistor, so as to slowly and safely bleed off the stored up charge inside (which can stay in the amp for a long time).

    Let us know how it goes. Maybe someone else will be able to give more detailed assistance.
     
  3. jetlag

    jetlag Member

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    Cheers for the info :)
    I'm yet to look at it yet. Something's definately melted, it's still stinking out the room downstairs.

    Thinking about it, I did plug it into a different socket than usual for the cab.

    However it was *exactly* the same as the other one (Not sure if anyone's familar with DSL's, but they have a 1 x 16 and 2 x 4/8 switchable ohm outputs.

    I always go mono 8ohm, usually using the left side 8ohm jack. This time I used the right side 8ohm jack. I can't see how that could have possibly caused an issue, unless it was some dust or something gathered in the jack due to non-usage and caused a bad connection? Hmm.

    Fortunately in times of need you find who your real friends are and had 3 offers of people to lend me amps, I'm probobly goign to use my friend's DSL50, same as mine just half the power for the gigs this week whilst mine gets sorted (hopefully).

    Can't wait till I can afford to buy something like an Orange Tiny Terror or something as a backup for me/bands other guitarist for gigs/tours etc.
    Anyway.
    It's a bit late to go inspecting now. I'll leave it till tomorrow.
     
  4. oldrockfan

    oldrockfan Well-Known Member

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    burning plastic smell... good news when that is the symptom it is usually just a matter of looking around to find the overheated spot. As was mentioned, be careful not to get shocked while snooping around. I've seen the common melted wires but it could also be a cap or resistor that gave out so take your time looking around. The problem will propably be easy to spot and then you can call a tech and tell him what you found to get an idea of repair cost. The bad news is amp repair seems to be going up in price alot lately. Least that is what I have found around Dallas.

    Good luck and hopefully it will be something simple for you.
     
  5. 1Way

    1Way Active Member

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    Ok, glad to hear you have some friends looking out after you.

    As far as waiting to examine goes, I would have suggested looking at it ASAP as smoldering, heat and smell can help lead into the right direction. For example, not sure if a blown tranny shows much signs besides being too hot. But if it's been a while, and it was smoking, you should be able to find the damage trail sooner or later.

    In any case, best of luck getting things repaired.
     
  6. ic_clint

    ic_clint Member

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    It needs to go to a tech, but hopefully it was just a power tube that shorted and took out some screen resistors causing a burnt smell.
     
  7. jetlag

    jetlag Member

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    Okay so I thought I'd plug it in today to see what's going on, not even the plugged-in dim light comes on now. Still haven't taken a peek inside since I've been at gigs all weekend/played one tonight.
    Should take it to ashop or something in the morning to have a peek.

    A few friends offered to lend me:
    Peavey 5150 (as long as I could find some tubes for it)
    A Peavey Bandit Combo
    Marshall DSL50 (most ideal since it'd have the closest sound to mine, just half power)
    Marshall 3315.

    I ended up borrowing the 3315 - might have been one of the best decisions gearwise I've ever made!

    The sound this thing made at the gig we played earlier on was amazing! So much clearer and defined than my DSL. Pedals sound better though it.
    I mean I've been championing valve amps over solid state for a few years now, despite using SS amps in band practice and college.
    I'm seriously considering fixing my Marshall and selling it so I can make an offer to my friend for this bad boy! :-X

    Playing another gig with it tomorrow (this time with my own cab too), so will see how that goes. :D
     

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