Hello, that fellow is the first time I go to this forum and I would like to ask for your help a few days ago, a horn of the brand arrived at my workshop atvio the problem that the client describes me is that when playing the music the Sound for no reason, so I set out to open the horn and check capacitors, transistors, regulators and everything until I found an ic 4558d which does not reach the negative voltage and check and change capacitors but remains the same; My question is whether it is possible to make an external source to feed the ic..I thank you in advance for your attention.