No output on main speakers

could be bad connections on the preamp IC's. You would have to have some soldering skills to be able to touch up the connections.

Generally speaking, an amp attempts to protect itself from heat, shorts, overloads and operator exuberance by refusing to turn on or stay on.

Overloads can be from excessive periods of high output or marginally low impedance loading by the speakers; and shorts would be wiring issues or a speaker blowing up.

You should be able to feel if it's hot. WHY is it overheating? Make sure it has sufficient ventilation on all sides and that vent holes are not blocked by dust balls. Ensure the fan (if equipped) is running as designed (some only operate on demand). Clean dust and debris from it.

If the amp comes back on after cooling, you're lucky. They only have so many self-protection cycles in their lives so continuously resetting or cycling their power without addressing the cause can do more harm than good.

If it protects immediately on a cool power up you should disconnect the speaker connections and try it '*****'. If it comes up then diagnose which lead(s) are shorted. If it does not come up the problem is internal and should be left to an experienced and competent hands-on tech.

Yes! it can be repaired, the technician will need to replace the audio output ic and maybe some drivers.

Make sure the speaker selector is in the on positon for the speakers you are using.

The most common problem found on FixYa for Audio Video Receiver's is:

My receiver say's "Protect" or turns on then off. What's wrong? Seven times out of ten it is a shorted speaker or speaker wire. To determine your exact problem, the first step is to disconnect all speaker wires "at your receiver" Next: Turn the receiver back on. If your receiver still says "protect" or turns off, it needs to be serviced. If your receiver stays on; reconnect your speakers one at a time and power back up after each speaker. You may find that after reconnecting all speaker wires it works! Most commonly the small braids of wire from the + to the - have touched and have caused the problem. In some instances, you noticed the problem only when turning the volume up. either way, make sure the exposed wires to your receiver are no longer than 1/2" long and are completely under the screw down terminal or slide in. When you've found the wire or speaker with the problem, your receiver will go back into "protect" At this point, disconnect the wire from the speaker at the speaker that may be causing the problem then test again.* Note* Make sure speaker wires do Not touch each other as this Will cause a short! If you turn the receiver back on and it stays on, you now know the problem is in your speaker itself. To test your speaker, you will need a multimeter. Set it to ohms resistance and touch the speaker terminals, if there is a short internally the meter will read "1......" If it's an analog meter, it will peg to the right. There's your problem. Now, within any speaker there are quite a few possibilities as to what could be causing the problem. Most common is a blown coil and the speaker needs to be replaced. Some speakers have internal crossovers (usually floor standing speakers) and may have a shorted or burnt board (usually very visible brown burn marks on the board) and can possibly be repaired if your handy with a soldering iron. Now, if you disconnect the speaker wire at the speaker and it still says "protect" Check your wire for the obvious cut or nail thru the wire if possible. If your system has wiring that runs behind walls, you may need to use your meter again. Disconnect the wire at both ends, keep the ends separated, put your meter on ohms resistance and touch probes to the + and - wires at one side. If the meter pegs to the right or reads "1...." the wire is shorted and needs to be replaced or repaired at the short. Hope this helps.

replaced power output amp

Check if you connect corectly the speakers wiresnand if they are right connected the audio amplifier Ic are damaged

Protet mode is a special diagnostic mode that starts when a fault is detected.

When in protection mode the unit is prevented from starting by protection circuit, so to prevent further damage.

Check the speakers and speakers wiring, a contact in speaker wires, or faulty speakers can send the unit in protection.

Try unplugging power cable for one hour or so. then connect cable back and see if you get rid of protect state. Sometimes accumulation of electrostatic charges inside circuit capacitors can kick in protect mode. In that case unplugging the unit from main for some times can get rid of electrostatic charges, and reset circuits by draining power completely.
If that was the problem, you will not get Protect when plugging back power cable.

If you do all the above and still get Protect, then there is a real fault.

In that case the unit may be disassembled and tested to find the fault.

If that is the case I suggest contacting the manufacturer at the number listed on the owners manual, or asking a quote on repair to a local technician.

The easiest way is to hook up your DVD/VCR combo directly to the back of your Sharp LCD TV, then run a component audio output from the TV to the audio input in the back of the receiver. Make sure you hook up your front, center and rear speakers correctly to the receiver, then go through with the speaker calibration steps - per manual, then it should work with no problem. Good luck!
Marc

If you do not here a click as soon as the power is turned on, (note you must be in a very quite environment no noise absolutely to hear this) then the amplifier has blown output transistors which are pushing DC current to the speakers.