Hi I have a Rotel RA-9308X amplifier. the left

SOURCE: rotel ra-820 amp speaker ports dieing

You may have blown a fuse on the left channel due to speaker wires shorting or a defective speaker. If there are no fuses on the rear of the amp there are probably internal fuses. They are usually glass with a small wire running from end to end. If the fuse is blown the wire will be broken. Replace with the same value of fuse.

SOURCE: Rotel Amplifier RA-9808X

Instead of replacing you can try and clean it. There are a lot of good contact cleaners out there.

SOURCE: Rotel RMB-1095 Power Amplifier Problem

Sounds like wiring problems. Unhook everything, then get owners manual for proper instruction

SOURCE: Are you able to provide a circuit diagram or even

I am sure I have fixed this model in the past. A lot of Rotel gear of this vintage, although sounding quite good, had been farmed out  to Taiwan for manufacture. This was back in the day before electronics came from China. But the quality of the build was often low grade, and hand assembled with custom made IC's and transistor arrays that are no longer available due to local manufacture(taiwan). Some gear was Japanese and better build quality.   Look for a 5 legged transistor (small black bodied device) device, or blackening of the legs of any  transistors(black death i call it).Is it possible to post an in focus  picture pof the internals to jog my memory on this amp. 

SOURCE: Have Rotel RB-1080 stereo power

Try to plug a set of headphones into your amp.

If only one is working this means that either you're not getting both signals into the unit (check the signal input connectors, resolder any bad contacts), the signal doesn't get to the preamp or from the preamp into the power amp or the signal does not come from the power amp (check solder connections on preamp and power amp components, also check internal connectors - unplug, clean, reconnect).

If both headphones work well instead, then you're getting both signals into the unit and the preamplifier and the final amplifier are OK, since many amps derive headphone signal from the power amplifier via some power resistors - check for any power resistors around the headphone plug or in the section that has wires going to the headphones plug to see if this is the case - if it is, this means that the signal does get amplified, but it is not getting from the power amp to the speaker - in this case, check the following:

--- speaker connector solder contacts on the circuit board could have some damage - resolder if necessary


--- A / B speakers selector switch (if there is one, it could be a physical switch or a soft touch button driven relay so check for both) - there might be a bad solder contact on the switch pins or the switch / relay contacts may be dirty - resolder and/or clean the contacts (if they can be easily accessed).


--- final amplifier section: bad solder contacts on any power transistors, voltage regulators, power resistors, diodes, coils or other components, including internal connectors (anyway, if both headphones work well, these are all unlikely because the power amp is sending both signals out OK, however, you may want to give it a check, just in case...)


--- delayed speaker turn on relay or other relays - check for dirty relay contacts, clean with some fine sandpaper (you need to remove the relay cover which can be a bit tricky / difficult to access, mostly it's a snap-on cover, could also be resin filled and therefore impossible to open).


It could as well be a bad power amp (do the headphones test), the above suggestions are just a quick look at some common audio amp problems and possible solutions.

Also, if your unit has got many hours of use, it would be fair to check the input signal connectors - the solder contacts do get damaged when you plug / unplug the RCAs many times.

Hope all of this is not getting too lenghty and confusing... just post me some feedback if you have questions.

regards

3rq8 (Triarcuate)