Power light turns from green to red protect mode and then there is no sound coming from my speakers

red light is usually bad like protection mode unless it is supposed to be red. amps are always green and red is protection indicator normally. look it up for your amp and if you bought it used you got ripped off

Mtx 801

on some amps there is a duel light. red and green usually. red means it is in protect mode or you didn't hook up your remote wire. if in protect mode, it could mean a number of things. did you hook it up with speakers and everything?

diconnect all your speakers from the amp and see if the light turns green. if it does, reconnect one speaker at a time to find out what speaker is making the amp go into protect mode

Is the red light flashing at first?
The unit may be going into protect mode. Lets hope it has done the job and the receiver has protected itself from failure.
Protect mode can result from speaker wires touching each other or the Amps metal case. Check that first.
It can also be caused by unstable ohm loads if too many speakers are connected to any of the outputs especially zone 2.
If you can remove all speaker wires and turn the unit back on. If it stays on, turn the volume down on the main zone and zone 2 if connected. Then reconnect speaker wires.

double check your wires aren't shorting out or power or remote wires aren't grounding. check if speakers are blown with nine volt battery

your amp isnt getting enough power to it you may need to install a compacitor unit

Sounds like you have an ohm problem, Tryy hooking the positive from one speaker to the negative on the other speaker. Then hook the negative from the first speaker to the negative on your amp and the positive from the second to the positive on the amp this will drop your ohm load and the amp should stop going into protection.

the amp is going into protect mode due to something wrong in the amp or some thing in the wiring to it ooh yea if you are getting 18v power to the amp that is way to high it should not be higher then 15v if the amp is in protect mode it will not play at all.

It probably has shorted output transistors. To eliminate other possible causes, read through the following page.

Amplifier in Protect Mode - Troubleshooting

Let me know if you have any other questions.