i came home one night with my stereo working fine and then the next morning it wouldnt power up. It isa 98 civic ex and an aftermarket stereo. All the fuses are fine and there is power going into it because i tested it with a light bulb thing ( not sure what its called). anyone know what this could be? or is it just the radio (i hope not lol)

 

Did you check the fuses under the hood too? I think the constant 12V (yellow wire on an aftermarket stereo) is powered from there.

Edit: If you have power on both the red and yellow wires, and a good ground, there may be a short in the speaker wiring, which will shut down many aftermarket stereos. Or of course the final conclusion is the head unit itself is defective.

 

the stereo has a fuse too, check that out next. then take a volt meter and start testing from the beginning of the circuit. stop where you lose power.

 

dont forget to check the remote wire. if its not getting a signal from you ignision it wont power up even if you have power to the head unit via red and yellow wires

 

the remote wire is for the amp. the stereo will still have power.