Blown tube? Fuse? Huh?

Discussion in 'Amps and Cabs [BG]' started by NioeZero, Dec 9, 2001.

  1. NioeZero


    Sep 2, 2001
    I sat down to play guitar yesterday, (Yes, I play guitar as well as bass. Help me out anyway.) and I think I blew a tube, or something. I have no real idea how to maintain or diagnose amps, so I'll just describe what happenend, and hopefully, someone will be able to help.

    I switched on my amp (A fender bassman reissue).
    I sat down to change a string while the tubes warmed up.
    About five seconds after switching on the amp, it made this loud "KKKKRRRRCHKKKKKKK" noise, and died.
    No sound.
    The power switches do nothing. Flip them on, no power light.

    (I guess I mistakenly threw the Standby switch as well as the Power switch while turning on the amp. I've heard this is a bad thing, that you're supposed to leave the amp on Standby until the tubes are fully warmed up.)

    Thanks in advance for any help you might be able to give me. I would've posted this on a guitar forum, but if you've been to or the like lately, you'll know why I posted here.

    Thanks again.
  2. BigBohn


    Sep 29, 2001
    WPB, Florida
    Arggg, sorry buddy. I play guitar as well, into my Fender Hot Rod Deluxe, and I think I know what you're talking about. That big sound is coming from something, I'm not sure if faulty speaker wiring, or hopefully not a blown transfuser. Thats quite a bit of simoleons to get one of those fixed. Take it in to a pro amp repairer and see whats going on. :confused: :(
  3. Tapp


    Aug 29, 2001
    USA, Mississippi
    If the pilot light doesn't come on then you blew your mains fuse. Do not, I repeat DO NOT replace that fuse with a higher rating or do the aluminum foil trick to get the amp going.

    Go to your local Radio Shack and get a fuse with the SAME rating (look on the back panel of the amp and it should give you this) and plug it in and try it again. BTW, when you change the fuse, UNPLUG the amp from the wall.

    My first instinct is you may have had a wall voltage surge (it does happen sometimes). My second guess is that your rectifier is bad. Do you have a tube or SS rectifier in that Bassman?

    Plug a new fuse in and let us know what happens. If it blows the new fuse don't plug another fuse in unless you like wasting them.

  4. Tapp


    Aug 29, 2001
    USA, Mississippi
    On second thought since you heard that noise, check to see if your speaker leads are connected properly and not shorting out (touching one another). It may very well be a power or rectifier tube (if you've got a rectifier tube).

    Do you have another set of 6L6's? If so, change the fuse and plug them in temporarily and see what happens. If you determine it's a power tube that went south then when you replace them you will need to have the bias checked before you play out with the amp.