My Samsung home theater HT-X30 failed to operate with an error display "PROTECTION" it only says in the manual to press the STOP button for 5 seconds to reset then turn the power on again, but unfortunately nothing good happens in several attemps, anyone knows this error "PROTECTION" is all about?
i think its telling you there is a short somewhere. try unpluging everything (speakers, outputs, and inputs) and see if the message is still active (probably have to cycle the power). then plug in everything one at a time, to see what wire, cable, or device may be your trouble.
I've tried everything in the process of elimination as far as to detaching all the speakers, checking the speaker terminal jacks for possible short circuit using multimeter and even removing the top casing eliminating the connection for each circuit boards while powering the unit. It seems the one that causes the problem is the amplifier circuit board, tried disconnecting the ribbon cable between the amplifier board and the main board, powered it up and no more protection error was displayed. Now I need to go deeper in to component level check such as the driver transistors etc., I had already checked all the electrolytic capacitors, mylar capacitors, the exhaust fan, the inductors and they all seems to be fine, what I have not checked so far in the amplifier board is the power-amp IC's, I don't know I still need an expert advise please help.
Some of these checks your doing (with a voltmeter?) may not give you help eliminate a problem circuit. The protection circuit, usually a relay, could be cutting power to the amplifier cct, or just the outputs. Class d amps are difficult to test without the right equipment.
Your going to have to find a service manual, troubleshooting guide, and/or schematics if you want to go deeper. Google will find you a few places to download these in pdf.