New Phono Amp?

I have a Pro-Ject Phono Box SE about 3yrs. old, the left channel seems to have gone bad. When I got the phono amp I had a Denon 3805. I did notice a difference when using the Pro-Ject phono amp instead of the Denon phono input. I know have a Pioneer Elite SC-25 rcvr, wondering if the Pro-Ject phono amp is that much better than the Pioneer phono input. It would be a real hassle to hook up to the Pioneer phono input. I would rather not do this if I'm going to wind up replacing the pro-ject phono amp anyway.
No sound from the left?
Make sure you check your cartridge leads or play with Pioneer phono input and see if both channels work.
I personally don't see a reason why small signal component should go bad within such short period time, but more than sure that the internal problem to fix is just as simple as possible blown fuse or cracked soldered connection in input RCA recepticle. Opening the box and visualizing or jerking around RCA recepticle if you get some signal back make sense even for the one never touched circuit elements of electronic equipment. If you're not comfortable with that you can bring it to techie to fix which might be more reasonable than just purchasing a new unit.
Anyways if bad comes to worst, I buy broken components in case you decide to go for the upgrade bug and can offer you some reasonable compensation for your broken unit that might make more sense to you vs. fixing it.