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Grounding Issue

Discussion in 'Amps and Cabs [BG]' started by Tyler Hole, Sep 11, 2004.


  1. I have a '78 Peavey Mark III head and there is no ground prong on the power cable, but there is a spot for one (like it fell out) and I was wondering if I could get that fixed easily by someone or do it by myself and if it's easy enough to do, how? Thanks for any help.

    -Tyler
     
  2. sheepdip

    sheepdip

    Apr 14, 2004
    Go to a hardwre store and get a new 3 wire end and install it.
     
  3. Lyle Caldwell

    Lyle Caldwell

    Sep 7, 2004
    Memphis
    Sounds like a previous owner snipped off the ground prong. Don't ever do that, btw.

    If the power cord is detachable, you can get a 3 prong replacement at any hardware store or electronics store.

    If it's hard wired, take it to a tech. There are voltages inside amps that can kill you even when the amp is off.

    No offense, but someone who asks this question is not ready to be poking around power transformers and power supply capacitors.
     
  4. None taken, the only reason I asked if I could do it was because I've fixed wiring in my basses before and am confident I won't totally screw it up.
     
  5. And another question...what exactly do you mean by this?
     
  6. Lyle Caldwell

    Lyle Caldwell

    Sep 7, 2004
    Memphis
    If the back of the amp has a female socket that the power cord plugs into, it's detachable. If so, no problem, buy a replacement.

    But if the power cord is attached to the back of the amp, it means that it is hard-wired to the insides of the amp, and you could get fried if you touch the wrong wire or component. Some older amps are built like this.
     
  7. Lyle Caldwell

    Lyle Caldwell

    Sep 7, 2004
    Memphis

    It's not a matter of you screwing it up- it's a matter of the amp stopping your heart. Remember, the inside of a bass contains millivolts, which you won't even feel. The inside of an amp contains 300-500 volts, all of which would love to kill you.
     
  8. Thanks for clearing that up, mine is defenitely hard-wired.

    Couple questions on this right here...one, why would anyone do that? And also, when you say snipped, it sounds to me like the person cut it off and left some of it still in...which sounds odd. Here is what it looks like:

    [​IMG]
    [​IMG]
     
  9. sheepdip

    sheepdip

    Apr 14, 2004
    For crying out loud! Hard wired or not, just go to the hardware store, get a new end, clip off the old one, strip back the wires, black is hot, white is common and green is ground. You don't need to get anywhere near the inside of the amp!
     
  10. Lyle Caldwell

    Lyle Caldwell

    Sep 7, 2004
    Memphis
    Sheepdip,
    Not to be argumentative, but a replacement end is just asking for trouble in the long term. That plug will be under stress, stepped on, get pulled, etc. All of which will cause failure eventually. Probably in the middle of a gig.

    A good tech can replace the whole thing for $10 or so.

    Tyler,
    A previous owner probably had a ground loop or a wall outlet with only two prongs, so rather than finding and fixing the problem, or even using a ground lift adapter, they just pried off the ground prong of the plug.
     
  11. sheepdip

    sheepdip

    Apr 14, 2004
    If he doesn't buy a POS end and installs it correctly there should be no problems BUT a molded end would be more secure.
     
  12. Lyle Caldwell

    Lyle Caldwell

    Sep 7, 2004
    Memphis
    I agree, replacing the end is an option. I don't think it's the best option, but it is an option.

    That reads very confrontational, but it isn't meant that way. So many things sound wrong over the internet that would sound fine over a beer.
     
  13. Mike Money

    Mike Money Banned

    Mar 18, 2003
    Bakersfield California
    Avatar Speakers Endorsing Hooligan
    The prong stayed in the wall when i unplugged my TNT yesterday... i was afraid to touch it.
     
  14. Woohoo! I'm still alive :D I got a new 3 prong and put it on, no more grounding issues! I'm stoked.