Amps broken??!

Hello, I’ve been having a problem with my amplifier for a few days, which I can’t explain. 2 woofers (rolls) and 2 boxes (hutablage) are connected to the amplifier. Now all of a sudden it gets no more power, although power cables, fuses etc. are fine. The power lamp lights up, but there is no sound. I removed all cables and reconnected, again no sound. The woofers or boxes are not broken, have checked everything individually with the colleague, so it can only be on the Ver My question now: why does the amplifier not get enough power, or better said not enough power? (Enough current that the lamp concerns, he has yes).And another question: For example, if I buy any parts from eBay USA (boxes, amplifiers, DVD players and TFT), can I use it here without any problems? Many greetings sunrise