GK 700RB-II problem with turning on

Mongolian Bass · #1 12-08-2010, 07:25 AM

Well I had just bought a 700RB-II on craigslist and it worked fine for a while, but now when i turn it on the power light stays red and I don't know what the problem is. Has anyone experienced a problem like this or know anything that may cause the problem?

groove pump · #2 12-08-2010, 09:41 AM

Haven't had much experience with G-K myself, but I've only been hearing great things lately in terms of their customer service. If you haven't pinged on them yet, they might steer you right in a hurry.

craig.p · #3 12-08-2010, 10:52 AM

What if you DON'T connect a speaker cab at all? Does the light still stay red?

Mongolian Bass · #4 12-08-2010, 11:06 AM

Quote:

Originally Posted by craig.p

What if you DON'T connect a speaker cab at all? Does the light still stay red?

I tried doing that, and I switched the power cable from my 1001RB to see if the cable had any problems and it didn't change anything. I also tried both power cables with and without my Neo 4x10 cab connected to the amp. I forgot to mention that the mute light still switched on and off but the -10db, or however much, light did not turn on when I tried it, if that means anything.

craig.p · #5 12-08-2010, 11:27 AM

Guess you could pop the cover and see if anything's come loose or unsoldered in there. Look for cold (non-shiny) solder joints, too. And for anything that might've fallen in through a vent, e.g. paper clip.

Barring that, I hate to say this but it might be time for a trip to the shop. A 700RBII is some damn fine kit, so it'll definitely be worth the repair cost. And then you'll know you're running an amp that's been fully checked out. (Look on the bright side.)

Only other thing I'm wondering is whether the unit ever ran really hot, e.g vents blocked, fan never started up, etc. But it's all academic since it probably has to go in anyway, IMHO...

Wes Whitmore · #6 12-08-2010, 11:32 AM

If it stays red and never goes to blue (which is also when it goes to a usable unmuted state a couple of seconds after it is turned on), then it needs serviced. GK has authorized service shops, but I would contact GK directly and let them repair it.
Wes

Mongolian Bass · #7 12-08-2010, 06:47 PM

Well, I changed the fuse today and now it works and the light turns blue. I still think I may still take it to a service center to get a check up. Has there ever been an incident such as this, where the amp turns on but not fully because of the fuse?

98dvl · #8 12-08-2010, 11:43 PM

Contact GK...

How old is the head? I had a similar problem with mine back when I owned it.

I sent it in, told them I just bought it used off e-bay. I also explained that I had taken it in to an authorized shop when I was having some problems, and they replaced the input jacks (I think that was a common problem for a while). Then, a week or so later, it did the "red light not turning blue". They actually fixed it for free. I think they just had to replace one of the circuit boards inside. They never said why they didn't charge me for the parts, I just thanked them immensely. I only had to pay shipping back and forth.

This was a couple years ago, so your mileage may vary, but it's worth a shot.

Mongolian Bass · #9 12-09-2010, 04:34 AM

Well, I looked closer and I forgot to check out the type of fuse that was in it the first time, but the fuse in it is not right. The fuse is at 8a 250v and it should be 15a 120v.I think that maybe the fuse was on the edge of blowing and the amp wasn't responding right, but i don't know enough about fuses to assume anything safely. So I am going to get the right one and take it to a service center. The guy I bought it from said be bought it new a year ago from guitar center.

craig.p · #10 12-09-2010, 05:15 AM

15A is what the manual specifies for 120V. But that does seem awfully high current draw for a 700. An 8A fuse would pop at full sustained power or would eventually give up after having run at close to break voltage for many hours. BTW, fuse voltage rating is n/a when it comes to break current. Just use a fuse that's rated for 120V or higher. 250 is fine. If it were my amp I'd use a 10A or 12A for better protection, based on the 700 current-draw spec.

Interesting that the amp would show any signs of power when its fuse is blown.

Mongolian Bass · #11 12-11-2010, 05:23 AM

Well it definitely wasn't the fuse, the same problem is back. I am taking it to the service center today to hopefully find out what is wrong with it.

Mongolian Bass · #12 02-12-2011, 09:28 AM

Quote:

Originally Posted by 98dvl

How old is the head? I had a similar problem with mine back when I owned it.

Well I forget the exact specifics but if I remember correctly it was a blown amp and the circuit board that was the problem. And how old is it, I think the shop told me it was from 2007. Was your 700rb made around then? I really have no idea what to do with it now. The repair shop said it wouldn't be worth fixing for the cost. What do people do with blown amps that can be fixed other than throw it away?

FretlessMainly · #13 02-12-2011, 09:34 AM

That's a drag. I have a 2006 700RB-II and I've never had any problems with it, but no amp that retails in the $500-$700 range should turn into scrap metal after only four years.

I would call GK on Monday and see what they have to say. They've been helpful to me in the recent past (cabinet issues).

Hopkins · #14 02-12-2011, 11:32 AM

I think that GK will change the whole board for a couple hundred bucks. I think that is worth fixing.