help! my ampeg svt 200t is acting up!

Discussion in 'Amps and Cabs [BG]' started by berettapunk, Jan 17, 2013.

  1. berettapunk


    May 2, 2012
    Newark Ohio
    Alright, heres what it is doing, with all my bass guitars as well so i know its not the bass.

    The volume level drops and sounds like the head has turned itself off. The amp light is still on, and when i unplug the bass cable and plug it back in it kicks back on like nothing happened.

    Im baffled and my local shop i always go to doesnt know as well. They have a amp head specialist that does amazing work, but im trying to figure out if its going to cost me an arm and a leg to repair first.

    I have it plugged into a 4 ohm ashdown abm 414t 4x10. I know its not that because it acts the same way when i plug it into my 8 ohm 1980 fender bassman 115.

    If anyone has any clue id greatly appreciate it! thanks!
  2. It sounds like the amplifier chip is going into a protect mode, either thermal, or output short. The nominal 4-ohm load of your cab is most likely too much for it. Isn't the svt200t only 8-ohm rated? If so, you may have killed your amp.
  3. i had the same issue through a friends 200t, believe the one i played had some kind of problem with a short or dirty jack in one of the jacks on the back. it was acting similar to yours and if we smacked it in a certain place on top, it would come back in. i became a pro at hitting it mid song before i could get a new rig.
  4. berettapunk


    May 2, 2012
    Newark Ohio
    no, they are rated at 4 ohms 350v and 8 ohms 200v. i used my bassman 115 which is only an 8 ohm first because i only recently purchased the 4 ohm ashdown. it did it with the bassman long before i ever had it plugged into the ashdown, then again im probly the 6th person to own this as it is an early to mid 90s model. the guy i purchased it off of said he had it for 8 years. ive only owned it a few months :p

    thanks for the suggestion, tho a friend i spoke to just a little while ago scared the crap out of me by saying it could be a transistor.

    ive checked the back to see if it was overheating at all, and its not very hot when it acts this way so im not sure whats going on still.
  5. berettapunk


    May 2, 2012
    Newark Ohio
    lol, well if its that simple i wont be too worried about getting it repaired. im mostly worried its going to be a major component that needs replaced. i havent tried smacking it yet tho. ill let you know how that works lol.
  6. if memory serves me, i believe we were able to plug and unplug a cable into the faulty jack repeatedly and it would temporarily solve the problem. possibly by dislodging some gunk? this was not my head and it was a couple years ago, so memory is foggy at best!
  7. Bets are the effects return jack. You can use an instrument cable from effects send to effects return to bypass the internal contacts in the effects return jack.
  8. berettapunk


    May 2, 2012
    Newark Ohio
    if i leave it on long enough and not mess with it, it fades back in and out a few times, then it finally came back on for a good 10 mins. seems like something inside of it is finally giving out.
  9. ;)
  10. mine was doin the same thing, i think bstring has got it on this one. plus, ime bstring always gives pretty solid, straight up advice. you're in good hands!
  11. Jerrold Tiers

    Jerrold Tiers

    Nov 14, 2003
    St Louis
    Likely a bad connection..........

    Troubleshooting hint:

    Any amp that works again *after* the problem is noted (if whacked on top, or after it cools down, etc) is much less likely to have a major component issue than one which messes up and stays that way.

    It's not "impossible", but it's a lot less likely.
  12. beans-on-toast

    beans-on-toast Supporting Member

    Aug 7, 2008
    With any problem like this you have to go about it methodically. Start by cleaning ALL the jacks and pots with Deoxit. Loosen all the jack and pot nuts and check that any ground contacts are clean. Check and clean the harness cable assemblies, there are several in that amp. Pressing them in (reseating them) when the problem occurs may help.

    Then start breaking it down. Test the preamp at the effect in and out, the DI out to see if the problem lies in the pre or the power amp. Then break down each sub-section in-turn.
    Taylor_Bassman likes this.