JVC deck, bad preouts

Symptom:  Sub pre-outs dont work they way they should, even with sub volume at max and freq at low, the deck will not bump the subwoofer unless the speaker level is at 25, and even then it's still weak.   Most likely, a bad ground wire, as in the pre-outs (sub/speakers) arnt getting the proper grounding.

So Anybody wanna start off with what to do?  It's a JVC KD-LH300 deck, I disconnected the Sub Pre-out from the board already, and tested the continuity and got a 0.3 reading, which is pretty clean connection because as I touch the two leads of the multimeter, it reads 0.3 for reference.   Anybody know where the pre outs RCA's get their grounding from?

Here is a picture of the insides of the deck, it might take a while to load as the picture is like 667kb's, large enough for people to magnify certain sections of the picture.

https://img.photobucket.com/albums/v519/parad0xs/2006_jan_13005.jpg

Heres the piccy

Yeah but the problem is the rear speaker outs have the same problem.

I checked the ground connection on the RCA's, by checking continuity by touching one end of the multimeter on the case, and the other end on the outside portion of the RCA's, and I mean all the rca's includling speaker outs, and sub outs.. and they are all the same reading of 0.3 which means a decent connection.  Any other idea's guys?

Let's get this straight...you're trying to power a sub with the deck?