Help with hookup

The model number of your "preamp" is actually a solid state power amp are you sure that's right?
https://www.hifiengine.com/manual_library/mcintosh/mc2300.shtml

@fortin, your original post indicated the " m " before the c2300. The mc2300 is a power amp, which is why the question was asked. Now that we have that out of the way, describe to us the hook up, please, so we can help you. 

Well I have output main on preamp going to main balance inputs and speaker output 4 ohm to speaker

First make sure you're selecting the correct source and the speakers on the preamp and then add some volume to see what happens. If that doesn't work, then you'd need to dig deeper.

Double-check the mute button too.

I did check the mute button, and it was off. I have the speakers coming out of the amp not the preamp. I didn't see that it could come from preamp.

Two things to try. Do you have any sound if there is a selector for mono/stereo and you select MONO?
Second, if there is a TAPE monitor button continuously press that on and off to see if there is any sound. Ideally you would spray Deoxit 5 as deeply behind that button as possible and depress many times. Often an unused switch which is never used can develop oxidation and become engaged preventing sound coming directly from the source.

This might be a dumb question but I will ask anyway....
What are you using as an input source? CD player? Streamer? Phono? Make sure you have that input source selected and then do you see the needles on the c2300 moving as you turn up the volume ?
try multiple sources if nothing is working could be your main output tubes possibly 

Also try using output 1 or output 2 and select that output on the front of your c2300 

On the back panel of the MC352, there's a "INPUT MODE" selector, make sure it is at "BALANCED" position. 

https://img.aussieaudiomart.com/uploads/large/1807777-mcintosh-mc352-power-amp-excellent-condition.j...

Thanks! You have given me some things to try. The needles do move on both pieces when on. And I can hear through the headphones. 

As the meters on the mc352 are responding to the signal from the preamp, I suspect " it " is at the amp end. What are the speaker wire connections you are using, both at the amp end and the speaker end ? If you are using bare wire, make sure enough insulation has been removed from the cable ends to make contact, but not so much, that the positive and negative wires are touching ( I am sorry, I have seen this a few times in my lifetime ). This scenario will short the output ( no sound ). Was the equipment working properly, as far as you know, before you acquired the pieces ? Sorry for the questions......just part of trying to help.....

Here is what I checked-
Set on balanced and stereo.
Speaker cable is a u shaped audio zen cable, not bare wires.
Input is Dvd on preamp and selected that input.
Tried pushing tape moniter button several times. 
It did work very well, but he had been sick for about a year and didn't use it then. 
Using with CD player. Maybe it doesn't like The Temptations? 
Mute button not pushed on. 
I appreciate so much all the help and ideas!  We will keep trying .

 P.s.- you guys and girls are truly the best!

It's getting to the point when you really need to try to borrow from someone or somewhere a power amp, to swop into the system.  If it works with the replacement, then the guilty party is likely the power amp you have; if it still doesn't work, then that points to the preamp.

Do you have a multi-meter? If you do then put the leads on the speaker posts and see if you get a reading . With music playing the meter will fluctuate!

The puzzling thing about all of this is, the power amp meters are responding to the signal from the preamp, so, the amp is receiving signal. It needs to be at the power amp, somewhere, or, the speakers themselves. I am with twoleftears and yogiboy, on this one....

ide hook a different amp (even an integrated if you don't have another power amp)to the speakers or different speakers to the amp to see which is not performing. my guess is either the connection between the power amp and speakers or the power amp itself. the preamp (and the link to the power amp)is good since the power amp gets signal and there is sound through headphones.

Hmm. Ok, I have a Audio Space tube amp I can try. I have to have to get it out to take pics of it to list it anyway and I know it works. Or maybe the Sony,it works too and is much lighter.  I can't believe I didn't just do that first. DUH. We are going to figure it out. Thanks for your expertise!

So, this morning when I was trying some things I found that when I had it hooked up to CDR the tuner on CDR and I turned it all the way up I could hear music in the amplifier but not the speaker,. So I tried to change out the cord to the speaker and that didn't make a difference. I will try different speakers and see if that is the problem and check the output terminals to see if they have something coming out of them. Sorry I don't know all the fancy words, but I think you get my drift. As always, thanks for any advice that you have!

If none of the above work and you can't detect a voltage at the outputs then it could be that an internal component failure has tripped the DC protection circuit. If DC is detected in the output signal it is shunted to ground to protect your speakers.

You might want to try single ended connections between the preamp and amp ( rca to rca ).