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Lights on, Nobody's home... any ideas?

Discussion in 'Amps and Cabs [BG]' started by gustobassman, Jul 24, 2012.


  1. gustobassman

    gustobassman I'm only here for the after party.. Supporting Member

    Mar 31, 2011
    Sandy Eggo
    So tonight at rehearsal when i turned on my 800RB it made a weak little growl and then stopped working altogether. I tried/troubleshooted everything, it's definitely the head. After changing out most of the cables i tried to plug in again and i got a low hum from my speakers. The cables/cabs worked absolutely fine through the studio owner's own Sunn head.

    The power light is coming on, however there is zero sound. Is this a blown fuse? I've already made plans to take it to a tech tomorrow, but if it was something simple like a fuse, i wanted to at least try. The last time i had an issue it went completely, no power light, nothing.

    Any ideas?
     
  2. dannylectro

    dannylectro

    Aug 2, 2010
    Atlanta, GA
    I've owned and used GK800 and 400RB's since around 1985-86. I've never actually had one fail on me. Ever. We might be plowing new soil if you get my drift.
     
  3. gustobassman

    gustobassman I'm only here for the after party.. Supporting Member

    Mar 31, 2011
    Sandy Eggo
    Well, i've only had to replace 1 transistor and the power switch in a 10 year period. Last May it took a crap at the end of a set, but from what i read on the work order, it was just loose connections.

    The whole light coming on and nothing else happening is new to me.
     
  4. JimmyM

    JimmyM

    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    LOL! Yeah, no GK ever broke before...except for the broken ones I've seen ;)

    Won't be a blown fuse if the power light is on. The one thing you could try is to hook a cable up into the effects send and out to the effects return. If the sound comes back, you likely have dirty contacts in your effects loop, which you can clean with contact cleaner or inserting the plug in and out a few times fast. If that doesn't work, take it to a tech. Doesn't sound all that serious to me, although I'm not a tech and I could be wrong. Hopefully not.
     
  5. gustobassman

    gustobassman I'm only here for the after party.. Supporting Member

    Mar 31, 2011
    Sandy Eggo
    ZING!!!

    Ha, i'm with you on that. I plan on taking it in to the tech tomorrow. That place is a whole other issue... It's the best shop in town, only open 5 hours a day (!!) and even less on saturday. Turnaround time sucks. The guy does fantastic work though...

    So i never use my effects loop. Would that really be an issue if i never even use it?
     
  6. Loop an instrument cable from the effects send to effects return jacks. Sounds like the effects return jack internal contacts are in need of cleaning.
     
  7. Yep that is why it does it. ANY amp with a serial effects loop can and will have this trouble. Even the "perfect" Ampeg, whoever made it that year. ;)
     
  8. JimmyM

    JimmyM

    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    Yeah, what he said, but without the unnecessary jab at my beloved Ampeg. They've had amps break too, yes. There...I admitted it, Jon. Happy???
     
  9. gustobassman

    gustobassman I'm only here for the after party.. Supporting Member

    Mar 31, 2011
    Sandy Eggo
    Uh, oh... "and fighting out of the blue corner".... :D

    OK, i'll try that. Amp on or off? Speakers plugged in?
     
  10. Connect the cable with the amp off and then turn it on. The connection is a low voltage low current one and the corrosion is called "fretting". Even happens with other assemblies like automotive air bag connectors.
     
  11. gustobassman

    gustobassman I'm only here for the after party.. Supporting Member

    Mar 31, 2011
    Sandy Eggo
    Awesome. I love learning things. Should i connect a cab to it? This is totally new for me. I'm hooking things up right now.

    CRAP. I only brought one instrument cable back from the studio. i'm guessing i need to plug in my bass as well as the cable through the effect loop?
     
  12. Nice Jimmy. Seen Agedhorse help Genz customers, Hartke has had the same, Carvn, Mesa, Fender, anyone with a serial effects loop. The jack has internal contacts that connect the preamp to the power amp.
    Speakers connected BTW.
     
  13. gustobassman

    gustobassman I'm only here for the after party.. Supporting Member

    Mar 31, 2011
    Sandy Eggo
    Ampeg is just as good, if it's any consolation i have my Sansamp set to the SVT setting....sort of :bag: :p
     
  14. JimmyM

    JimmyM

    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    Hey, GK's fine by me, bro. They haven't lasted over 40 years by sucking. Ampeg's more my thing but I don't have a problem getting good sound out of GK stuff.
     
  15. gustobassman

    gustobassman I'm only here for the after party.. Supporting Member

    Mar 31, 2011
    Sandy Eggo
    It's all good Jimmy! Me dig some ampeg too. Years ago I had the B4R. I LOVED IT, until it was stolen.. along with my car. I got the car back... that sucked..

    So do i need another cable to do this test? I only brought one home. i need to plug in my bass and the effects loop right? If so i'll have to do this tomorrow.
     
  16. JimmyM

    JimmyM

    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    Well here's what you can do in the meantime...just run a plug in and out of each effects loop jack 15 or 20 times real fast, and that will usually knock enough corrosion off of them to try it out.
     
  17. Took me 10 years to let go of my last Ampeg. It just was not fair to have it sit in the corner unused. Too many bassist that wanted to own a V4-B. Still like the "Ampeg" sound and would play one tomorrow. So I am not anti-Ampeg just so the record is clear ;)
     
  18. gustobassman

    gustobassman I'm only here for the after party.. Supporting Member

    Mar 31, 2011
    Sandy Eggo
    UPDATE: I tried this. Nothing. However both the power and boost light were on. I'll try it with another cable tomorrow. Otherwise off to the shop!
     
  19. basscooker

    basscooker Commercial User

    Apr 11, 2010
    cincy ky
    Owner, Chopshopamps.com
    Had this trick work for me on a "dead" gk backline i got for free. just plugged it in and out once and it solved the problem (by the way, thanks again B-string for the tip-- i sold it for 150) so you're prob ok with just the one cable, Gusto.
     
  20. basscooker

    basscooker Commercial User

    Apr 11, 2010
    cincy ky
    Owner, Chopshopamps.com
    oops. sorry. better luck next time <crosses fingers>
     

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