QuestionHi. I've bought a new car and my subs don't work. I don't dig into audio stuff, but I do have a multimeter and a couple of hands. So, the setup is:
nakamichi cd-45z head, speakers are connected right into the head.
blaupunkt gta 4100 amp in the trunk, two 2xRCA cables coming in from the head unit, two subs on the outputs.
The red protection light is constantly on, the green power light is off. Once in about 4-6 seconds the red light goes off for a moment, the green one goes on and subs produce a thump (doesn't depend on what is playing or the volume on head, the same even when volume is 0). Then red light again... I checked the ground and +12v terminals with my multimeter, seems ok. So, is my amp fried, do I have a short circuit somewhere (maybe subs are fried?) or any other ideas? Willing to disassemble and check everything out. I checked all the connections to the head unit, they're ok, so unless the cables are cut somewhere in the middle, the head->amp connections should be ok.
AnswerHi Gene!
Disconnect the speaker from the sub amp and see if the red light still going on,(you need to turn the headunit off for a couple of seconds for the protection to reset) if it still the same measure with your multimeter on the amp speaker out (without any speaker) on the DC volt range if there is any voltage it means that the amp is blown and is sending DC to the speakers (more than 36v!)if you want to venture inside the amp just remove the cover but be carefull with the caps! they store the charge for quite long time and both rails added can have more than 70 Volts! so let it disconnected for some time before removing the cover.
