problem with amp, I think

I just bought  a new system for my car (Alpine CDE-9843 HU, Hifonics TX1505D amp, and 1 Power Acoustik Mofo15). I have hooked up everything correctly (as far as I know) but I am not getting any sound. My amp turns on but there is nothing coming out of the sub. I hooked up an old 6.5" just to see if it was the sub but all I heard was a low static. I called Hifonics to see what could be done but they said because I bought my amp from an internet site,( www.sonicelectrnix.com) they can't do anything about it but the guy did tell me that it could be something wrong with the output from the HU. The Alpine came from Best Buy so I went back there so they could look at it but they said the earliest they could look at it would be Friday. I read in some other forums about how people have had problems with their RCA wires and I was wondering if it could be that. Somebody please help me!

i have had problems like that before. try checking with another H/U. if you dont have another H/U to do this. you can get a cheep pair of RCA's and headphones. do some surgery and use a walkman or anything with headphone output for that matter.

it could be somthing with the amp. i dont know if you were getting what i was saying. what i was saying is to get sound from somewhere else into the amp . that will let you know for sure. i dont think its the cables. i think its from the H/U .i had a problem like this before . in the end i just used a line out converter because the H/U worked fine.except the preouts were shot. how many sets of preouts are on your H/U ?