Uneven speaker volume output

Have an all solid state system, and have recently noticed that right channel speaker is producing a louder volume level than the right. Before I begin to obsessively explore this issue, am trying to get read on the most common reasons for this occurrence, and add some sanity to my process of elimination. Any advice appreciated.
First of all, make sure your balance control is centered. ;) -- I'm not kidding -- I once spent a half hour trying to figure out why my left channel was louder before I realized that I had inadvertantly changed the balance. Then, check to make sure you have your speaker cables hooked up correctly so both speakers are in phase (negative to negative, and positive to positive, on both speakers).

Your post contains a typo, so I can't tell if it is your right or left speaker that is louder -- I'm going to assume the right channel is louder. Switch the speaker cables and see if the left channel becomes the louder channel - if so, the problem isn't your cable, speakers or placement. If the right channel stays the louder channel, then the issue is either the speaker itself, or speaker placement.

Assuming the problem is not the speakers or speaker placement, switch the right and left cable on the inputs to your amp (if using separates) or on your music source (if using an integrated amp or receiver) and see if the right channel stays louder. If it does, then you've isolated the problem in your amp/receiver. It the left channel becomes louder, the problem is your input source.

Now, at least, you know where the problem is isolated.
It may help some if you post your equipment. For example when you first try swapping the left and right speaker wires, if your preamp/receiver has a stereo/mono switch, set it to mono. Try the switch(st/mono) first just in case. If the sound balances out to equal, that should rule out the speakers, and power amp if it applies. On a preamp, switch the left and right inputs from your Cd player. Also the left and right outputs from the preamp outputs to your amp. If the same speaker still has a louder volume, that should rule the preamp out. If the opposite speaker gets louder, that would point toward the preamp. Do the same with your power amp. Switch the left and right inputs, and the left and right speaker outputs. If it stays the same same, the power amp should be ok. If the opposite speaker gets louder, that would point to the power amp. Only try one component at a time. There are to many unknowns now.
Hifihvn: Your help with this issue is much appreciated. Narrowed problem down to use of balanced ICS between amp and pre. Now to figure out which is the culprit. In the meantime, have switched to a pair of single ended cables that are working just fine. To my ears, no difference. Again, thanks for taking the time to help me out.Your advice helped to approach this more rationally than what might have been. Regards, maleja.
Rdavwhitaker: Response to Hifihvn goes out to you as well.

Muchas Gracias, maleja.
Glad to help, and glad you've found a work around while you figure out the culprit. Happy listening.