My Pioneer 690ub powers on, I can flip through the menus, and set everything.

But, I don't have sound from any of my speakers.

I tried them on a stock radio, so they aren't blown. so I'm thinking it's the head unit speaker outputs.

If my head unit outputs are blown, can I still hook up a 2-channel amp to my front 6.5's?

Or do I have to replace my whole head unit?

Trying to get my sounds right before I upgrade, so I can

Any help is appreciated.

I would check and make sure none of the speaker wires are shorting out. Including the wires in the wiring harness.

Is this a new unit, or something that just started happening?

Yes, it's possible for the RCA outputs to work even if the internal power amplifier does not, depending on what's damaged.

there are switches on the bottom of the headunit that will switch the internal amp on and off.

I know my pioneers and Alpine units had switches like that so you could turn the internal amp off if you wanted use an external aftermarket one.

I checked my radio/wiring harness & re-wired everything.

I think it's because when I hooked the amp up last time, I wired the speakers straight from the amp to the head unit & it shorted the outputs?

My deck still comes out & I can flip through everything. I disconnected the battery & still no sound.

Guess I need a new head unit & speakers now...