Need to see the wiring diagram for Yamaha guitar EG112C

https://www.google.com/search?q=rbx750a+wiring+diagram

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Check out the link

https://www.google.com/search?q=Yamaha+BB200+bass+guitar+wiring+diagram

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Possibly this web site, but I didn't register to verify that it is legitimate.

http://www.satsa.co/wiring/series-wiring-diagrams-yamaha-guitar.html

Series Wiring Diagrams Yamaha Guitar With images

http://ariabasses.blogspot.com/2010/11/aria-pro-ii-sb-1000-wiring-schematics.html

Sounds like the amp (or speaker) blew. Do you have anything else you can plug into the amp to test? If possible use a different cord to preclude that as a cause, too.

Try this link:http://patrick.murris.com/musique/guitare/wiring/Yamaha%20SG%20Wiring%20Diagram.jpg Hope this helps.

Find appropriate diagram at this site:

http://www.guitarelectronics.com/category/wiringresources/

Try looking at this site:http://www.guitarelectronics.com/category/wiringresources/ Here is a list of sites to look through:http://www.webcrawler.com/webcrawler300/ws/results/Web/guitar+wiring+diagrams/1/417/TopNavigation/Relevance/iq=true/zoom=off/_iceUrlFlag=7?_IceUrl=true&gclid=CLj5soncpp4CFRQpawod3GVYmw Also you can contact the Yamaha support through this link:http://www.global.yamaha.com/products/music/guitars.html I hope this helps.

check this diagram found here

http://images.google.com/images?hl=en&q=guitar+wiring+diagrams&um=1&ie=UTF-8&sa=X&oi=image_result_group&resnum=1&ct=title

Here is a bunch of Diagrams courtesy of google images.