Thread: Help needed not another amp to carpc question

First i would like to say hi i am new here.

i am in the process of installing a carputer into my car anyway i wired up my amp, sub and 2nd amp for the doors speakers and i tryed it on a headunit and everything worked fine the amps powered up and all worked all speakers worked as well.
i ran from the head unit using RCA then in to the amp then out of the amp standard speaker cable.
Then i decided to try my laptop in place of my headunit.
My laptop is not my car puter just wanted to see what the system would sound like through a computer.
Anyway i got a RCA to 3.5 jack adaptor and pluged the RCA into the 3.5 jack adaptor then pluged this in to the head phone jack socket on my laptop.
i left the remote turn on lead conected to the headunit so when the head unit is turned on it will switch the amps on then obviously i will come out of the laptop for sound any way i tryed this and for some reason the amps wouldnt turn on.
Then i decided to try the lapto through the line input on the head unit so i got the RCA leads pluged these into the line out on the head unit then i got another small RCA to RCA lead and pluged one end in to the 3.5 jack adaptor and the other end in to the line input on the head unit and tryed this and it worked my amps pwered up and i heard music from the laptop runing through the headunits auxillary in.
Any way i want to get rid of the headunit completly so i am wondering does anyone no why the amps wouldnt power when it was directly on the computer and any way of making it work.

i hope you can understand what i am trying to say above i no its a bit long lol Thanks for any help