GK Backline 600 has power but no sound

Danimal35 · #1 11-23-2011, 03:23 PM

Well, although I've been playing bass guitar for many years, I'm not at all knowledgeable when it comes to the electronic end. The other day, my GK Backline 600 started cutting out on me the other day until it stopped performing altogether. I assumed it was my battery for active pickups, but the passive bass resulted in nothing, as well.
Anyway, the power light comes on, but that is that. This is not under warranty and I would rather not put $200 into a $300 head, eh? The local repair wizard says $95 USD plus parts to fix her, so any constructive advice would be appreciated for my doorstop...er, non-functioning bass head.
Cheers,
Danimal

fdeck · #2 11-23-2011, 03:40 PM

Exercise the effects loop jacks. Plug in and out of each a few times. This is an Achilles heel of virtually every bass amp ever made.

Try plugging into the effects return, thus bypassing the preamp.

Do you get anything at all out of the speaker, such as just a bit of hiss and hum? Or is it really nothing?

Have you tried different cables? A different bass? Speaker? Never assume anything.

Danimal35 · #3 11-25-2011, 11:10 AM

Um...well....I tested it with my old Peavey 2-10/1-18 Enclosure and it appears to be fine. However, I've just never heard of of a speaker cabinet give it up so suddenly.
I pulled the cab apart and there doesn't seem to be any obvious burning around the input jack. The other side of the wires directly lead into the cone itself (I thought that was a bit odd).
Was this caused by an impedence issue between the head and speaker cabinet?
The GK at 300W has a 4 ohm minimum load.
The Peavy is rated at 200 Max Watts/4 Ohms.
The (non-functioning) Crate BE15 is rated at 200W maximum/8 ohms.
Again, this is where I wish I was paying attention in school versus dreaming of being John Paul Jones...
SO...this fixable or do I now have a dead 15" cone?
Thanks...Dan I. Mal

Hactar · #4 11-25-2011, 11:20 AM

Can you check the DC resistance of the blown cab?
Mayhap a bad solder connection?

fdeck · #5 11-25-2011, 11:56 AM

You can try 9-V battery test... just touch a battery directly to the terminals of each driver. You should hear a pop. Don't hold the battery there for very long.

Gubna · #6 11-25-2011, 11:58 AM

I had issues with a GK head years ago, and when I took it in the guy told me it was bad factory sodering. he redid it and it worked like a champ for years.

Danimal35 · #7 11-25-2011, 02:04 PM

OK...apparently, my head is fine. I did the 9 volt trick on the terminals and it did zip.
SO...any suggestions for replacement 15" speakers for a Crate BE15 cab? Oh...and thank you all...you've been effen awesome. Seriously...this lkind of thing is what makes the bass plahyers the coolest people in the band. Cheers...

Hactar · #8 11-25-2011, 11:22 PM

Well, I'm inclined to think that your cab might be okay.
If you have a loose connection/short/bad jack/bad solder problem, it would be easily fixable.
If your voice coil is cooked, you're shopping for a new cab.