Pioneer receiver overload
The "Overload" message usually involves the speakers or the speaker wires. Disconnect the speaker wires and make sure that they aren't frayed or damaged. (When you reconnect them, make sure that no loose wire touches the receiver case, speaker or another wire.) Replace any damaged wire. Make sure that none of your speakers have a lower impedance than the receiver can handle. (Most Pioneer systems have a 8 ohm limit.)
If the message persists, turn off the system. Disconnect one speaker at a time and try turning on the receiver and turning up the volume. If the error disappears when one speaker is removed, that speaker may be damaged and needs to be serviced. Do not reconnect the speaker to the receiver until it is fixed.
I hope this helps.