Yamaha m70 amp and c70 pre-amp right speaker stopped working

my guess is that the yamaha has pre-amp outs, most yamaha stuff does, and that is the one you should be using for the main, and hooking up to the onkyo, and letting the yamaha be your zone controler, and the onkyo be your remote amp for your second zone (if your onkyo had pre-amp outs it would work how your trying to do it, but it dont) so exchange there places, and run a pre amp out to any input of your onkyo, and you'll have total volume control of your outside speakers

Swap the speakers left-to-right to isolate if it's an amp or speaker problem. You have not indicated this was done.

Elaborate a bit on what you're trying to do if this doesn't work for you.

This unit has Pre Outs near the center of the rear panel for all audio channels which will allow you to use external amplification for any speakers you wish to use and the receiver will still control the volume.

See #12 on page 10 of the manual. Try retrevo.com

Just run RCA cable(s) from the desired Pre-Out jack to the input(s) on the external amp with its speaker(s) attached. Set the external amp's volume (if it has one) to very high, then leave it alone. Run through the Yamaha's speaker location and volume settings to level-match the external speakers to the rest.

If you want to simultaneously use the Yamaha-attached speakers for the same channels as the external amp you'll have to match the like channel volumes to each other using a volume control on your external amp, then level-match them as a unit to the other channels.

Check 3 amp fuses on bottom of unit and position of Pre-Out coupler switch. Should be on.

Assuming you're using the Surround Back speakers for their primary purpose, let's establish that there is something in the way of programming being routed to that speaker. Fire up the speaker level setup procedure and use any handy audio device (*) to see if a signal is present at the Surround Back Pre Out jack. If not, that speaker will never, uh, speak.

* For this test you could use your powered subwoofer. You DO have one, right? Just swap the RCA cable from Sub W Pre Out to the SB R Pre Out jack to see if anything appears there.

Go to www.yamahausa.com then support then authorized serice centers. Hope this helps

It sounds like you want to use the external amp rather than the internal one. If that is the case, just connect the output of the EQ to the input of the external amp. All you are doing is inserting the EQ between the amp stages now. Using the mx-1 rather than the internal amp is no different.

Dan

this could be the pre amp transistor or the power amp , it will need to be tested and other components tested also to make sure they are not causing the pre amp to fail or the power amp to fail
if its the pre amp it will be cheap , if its the power amp then it won't be cheap , other small components are cheap

electech

HI SIR .THAT IS NOT BIG PROBLEM.ALL YOU HAVE TO DO MAKE SURE THAT YOUR PRE HAVE THE FLL.1 PROPERLLY EARTHED(THE GROUND FROM YOUR AMP ALSO GOES TO THE PRE )2 ASK YOUR ELECTRONIC MECHENIC TO CHECK IF THER'S NO BROKEN GROUND ON THE BOARD INSIDE.

Check the A or B switches it could be they are turned off!