iMac 21.5 late 2009 no power up

iMac 21.5 late 2009 no power up

Hello. After having pulled out hair dryer from the electrical outlet my iMac has stopped working. the power supply and the fan was working but the screen was black. I turn it off with the power button and then power it on again but it does nothing. . Only Led 1 is on on the logic board.. with a new power supply again the same. We measure everything in the logic board(with schematic) and all it's ok. What else must do?