Aria made some good quality instruments, at least as good as production Fenders. They came out of the Matsumoku factory in a wide variety of designs and configurations. That J clone needs a pickguard, but if a standard J PG doesn't fit it, you could have one made for it. I like the Matsu basses and have found them to be good players.
The sound issue is pretty easy. it just means (1) checking the pickups to make sure they work, and (2) going through the electronics and making sure that you have all the wires connected and none are shorted.
Disconnect each pair of pickup leads and use a digital meter to see what the resistance is for that pickup. If you get infinite resistance, you have a bad pickup, which would explain no sound. If you get a reading, it will probably be in the (best guess here) 7K ohms neighborhood.
Most likely candidates for no sound are:
1) A broken wire
2) A bent output jack that's not making contact
3) A bad volume pot
There is plenty of information on the web about how to wire pickups, so a bit of homework will benefit you. There really is no single "best" way to wire up a J bass - many variations are possible.
