Problem with GK 700RB I combo fan

[Wes Whitmore]

I just pulled my 400 apart and I didn't find a sensor. Just hitting the heats ink would also work. Glad you got!
If you notice, there are 4 wires that go down into the cab Two go to the 15, and 2 go to the horn. I would verify that the two wires that go to the horn also go to the 2+ and 2- of the speaker cable that plugs into the amp. I use a couple of alligator clips and extend the +2 and -2 wires, and make a quick touch on a AA battery to see if it makes a pop. If so, the horn is good and you need to look at the amp as being the problem. Of it doesn't, then report back.
Wes

 

[B-string]

As far as the tweeter issue. First need to know if the horn works. Check for a loose wire at the horn, if none found does the cab section connect with a speakon cable or direct into the head? If with a speakon cable check the connector for loose wires at the 2+,2- pins. Cable disconnected (or internal leads in the head disconnected) use a 1 1/2 volt battery (small test leads will be helpful here) and touch the leads to the battery. The horn should make noise. If the horn makes a noise then the horn amp maybe bad or a problem in the crossover circuit in the head (I have never seen the crossover have a problem). You can email [email protected] for schematics or PM an email address as I have an older service manual (if schematics are useful to you). I believe the horn amp chip is available separate if you are better than average with a soldering iron.

 

[Stakes_Is_High]

Thanks for the suggestions Wes! I am continuing the tweeter thread on this link http://www.talkbass.com/forum/f15/tweeter-issue-gk-700rb-model-1-115-combo-873436/

So far the battery test has appeared inconclusive...