When you try to turn it on right after you plug in the power cord and flip the switch, does it beep then beeps again and transitions from green to yellow then flashing red in the end?
If yes, the PS3 has overheated and the only way to get that working temporarily if your lucky is to do a reflow of the main processing chip (reball of the main processor chip is the best solution long term but I don’t think there are any repair stores out there that offer that service)