My Stereo Says Protect And Shuts Down When Volume Gets Turned Up

This usually means that you have an incorrect "load" on your amplifier, so it is shutting down so as not to damage its circuits. (That's a good thing!) Could be an open circuit, ie a speaker disconnected, or a short, ie the positive and negative wires are touching on the way to a speaker. Could also be that your speaker wires are too light a gauge (too fine) and cannot handle the current when the volume gets turned up: see if they feel warm to the touch at the moment of shutdown.

In some systems having one or more speakers connected incorrectly (wrong polarity) could cause this. Also, if you are using speakers that are incorrectly matched to your amplifier, this will happen. For example, if your amplifier expects the speakers to have 8 ohm impedance but they only have 4 ohms, the amplifier will over-drive and shut down at high volume. (Also if you are using multiple speakers on one channel, note that 2 8-ohm speakers connected in parralel will only show 4 ohms impedance to the amplifier)

There could also be a failing component in your amplifier, usually either the main power supply or the final audio amplifier stage that drives the speakers,

First, make sure your speakers (all/both channels ie left and right and any subwoofer or center channel) are connected properly, no opens, no shorts, no frayed wires, and not corroded where they connect to your amp and your speakers. Make sure the speaker wires are not chewed by the family pet or damaged by furniture somewhere between the amp and the speakers. Verify the speakers are the correct impedance match, and that your wiring is heavy-duty enough to handle the power your amp throws at them. Listen carefully at lower volumes and make sure each component of each speaker (woofer, tweeter-horn, mid-range) is putting out sound without distortion. (If any one component within a speaker has gone bad, this will affect the impedance of the speaker and could cause the symptom)

Still a problem? next, if possible, get another pair of speakers (borrow from a friend or neighbour) that are the correct impedance for your amp, and connect them with new heavy-gauge wires, for example, 16-gauge household lamp cord wire. If that solves the problem then your cause is likely in your speaker wires, just replace them all. (You can also ask your friend to try YOUR speakers on HIS amp and see if the problem magically moves to his place! Then you know the problem is your speakers...)

If your problem persists with different speakers and speaker wires, bad news: your amp is likely failing. However even in this case, if there are cooling grates designed to allow heat from the amplifier transisters to escape, make sure the grates are clear, not blocked by dust or other equipment, and check for (and remove) a coating of dust inside, smothering the components... any of these things will cause the amplifier to overheat, especially at high volume when the most heat is generated, and shut down.

Finally, consider having a reputable electronics repair shop check out your amp with their diagnostic equipment

Good Luck!