From day one this Lenovo ideapad z70-80 has had issues with suddenly powering down in windows (7 or 10). I bought the...

This Might work. It seems to work in recovering a lot of Lenovo tablets. 1. Plug the power adapter into the Tablet 2. With the adapter plugged in, Hold down the power button for 20 seconds 3. Disconnect the power adapter from the Tablet and press the power button for 20 seconds. 4. Reconnect the power adapter and turn on the Tablet.

My first thought is a faulty power supply. As they age, they can deliver less power. So if your system peaks at 500 watts and your PSU is rated at 550, over time your PSU will be stressed as it can no longer reach it's rated power output and could fail, or even damage components in the system. If you can, try replacing it with a known good PSU. It's possible the motherboard has already been damaged as it's not powering on, so I'd not try again with that PSU.

This might help, but there is little to go on here. https://support.apple.com/en-us/HT201263

Could be a problem in many areas, but to really answer the question a model number would be helpful. I know I have fixed many driers with faulty timers and blown fuses. It could even be the heater unit itself that has gone faulty. But it's all a guess without that model number.

You just need a rca to Mini Jack 3.5mm cable. Ideally it should be an isolated cable, though a quick search did not find one. This is what you are looking for. https://www.bitebee.com/product-p/scoi6rca35a.htm

The parts look to be avalible, and there are videos of people fixing the ports on older ipads. This site lists one for sale. Looks to be a cheap fix. https://www.diymobilerepair.com/ipad-pro-129-charging-dock-port-flex-cable-assembly-white?gclid=Cj0KCQjwi97NBRD1ARIsAPXVWWDw...-a5t8TxETqczLQ_3faYs1ZiQN0aAsl2EALw_wcB