I burned out some resistors on the circuit board of my Roland

Posted on Feb 6, 2014

Burned out some resistors on the circuit board of my Roland KC-300 amp and they are so black that I can`t tell what they are. What kind of resistor is R82, R83, R85, R92, and R93 If R92 and 93 continue to get really hot. you may have something pulling too much current. I would suspect IC10, or transistor Q6 and Q7 in the headphone circuit. Thanks for the help so far. I replaced

I burned out some resistors on the circuit board of my Roland
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R82, 83, and 85, but I had to order R92 and 93 because no one in town had those resistors. I tried it again with just those in place, but the headphone jack still wouldn`t work and R92 and 93 were still heating up. Should I replace the headphone jack too, or is it possible that R92 and 93 are causing it not to work I think you have a problem with the headphone circuit. Those resistors supply the positive and negative 15. 4 volt supplies to the op-amps and mute circuit. If they those voltages were not getting through you would have no output at all. It is normal for 2 watt resistors to get hot, but not hot enough to melt the solder. That indicates too much current is going through them. Since the headphones are not working, that is where I would look. The HP circuit consists of IC10, Q7, Q6, D9, D10, and all the supporting caps and resistors. You have to see if your getting signal into IC10, out of IC10, and through C81 to R83 and R82. While the headphone circuit is the most likely source of your issues, it is still a good idea to try to confirm it or narrow it down through measurements and signal tracing. The schematic should help in that respect. Thank you so much. That ought to do the trick. Is there some way that I can contact you again if I have any problems after I get these parts and attach them Ask-a-doc Web sites: If you`ve got a quick question, you can try to get an answer from sites that say they have various...

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