It depends on the region, since they are region-locked. If you live in, for example, the USA, your PlayStation must be the U/C region model or have a 120v power supply. Check the region of your PlayStation, if it matches your region, it shouldn't spell disaster unless some idiot replaced the power supply with the wrong region. And no, they can't do both 120 and 240 volts (since they are region locked). If you want it to handle 240 AND 120 volts, you'll need to get a custom made power supply board.
Well, try opening the console and find the source of the sound. I feel like it might be a component on the power supply getting ready to pop. I've never had this issue, but my experience in the field has taught me that whistling noises usually come from dying power components. Measure the temperature of the board, preferably using a thermal camera so you can see anything overheating. What model is the playstation? This answer will be edited according to the response you give.
Unfortunately, I'm going to have to say you were ripped off. Very badly. The seller was probably a hacker who needed to get rid of evidence, so he dumped the evidence on you. Oh, and now the CPU is basically dead because the heat physically warped the silicon wafer in it. You will have to make very costly repairs, and it may drain your wallet by at least $100.00. Fortunately, Ifixit sells tools you'll need. Since I'm writing this from my PS4, I won't be able to copy links, so bear with me here. First things first, you can find YLoD repair kits here on Ifixit for $45. Get one of those. Next, buy a new fan, make sure it's the same type as the original. The new fan should spin without being aided. Finally, get a new hard drive. If I were you, I'd factory reset that console as well, who knows what sort of crimes against humanity the previous owner committed with it… If you need help opening the console, check out Ifixit's guides and look for Ps3 teardowns. Good luck!
Fixed it! Sony sent me a copy of the official SCPH-550X series service manual, and from there I was able to get the surface mount components replaced. C110 was a 1nF 50V ceramic, and turns out the dead short was from the IC, not the capacitor. I replaced both anyway. The controller port inductor (PS605) was indeed burnt out, so I replaced it with a Wurth Elektronik 1.5 mH surface-mount inductor. Now my PS1 works beatifully!
Check to see if there is an obstruction or broken mechanism in the tape cartridge sled assembly. Sometimes the fragile plastic mechanisms will break and prevent the tape from being pulled up to the drum. Or, you might have a foreign object obstructing the path of the arms that pull the tape out of the cassette. Give the assembly a good look and you'll probably find the issue relatively easily.
Apple keeps all of their parts and product information under wraps (yes, this even applies to the shells and cases), so you're not going to find anything online without the Dark Web. It's best to take it to a licensed Apple technician to get it repaired, since they are the only ones who can actually manage to acquire parts legally. Good luck.
You might want to take the entire keyboard assembly apart and clean each individual piece. I find that doing so is the best way to clean anything sticky; Keyboards, controller buttons, ect. You can find a guide to help you on this site. I can't link you to a guide since I'm replying from my PS4 and don't have a copy-paste function, but you should still be able to find the correct guide fairly easily. Good luck!
Apple keeps all of their product information under wraps, so you'd probably have to obtain that information illegally. However, I'm pretty sure the CPU is socket mounted… I would check just to be sure, but be careful if you decide to check; Apple doesn't have parts available to anyone other than their licensed Apple technicians, so don't break anything. Good luck.