Try cleaning up the sim card and the place it goes in, try reseting the phone to factory, if that doesn't work go to your carrier and get a new sim card. If after all that it still does not work the sim card reader on your device is damaged and you could repair it but it will require soldering.

If you have a Google account linked to the tablet you may be able to do a reset using that google account, if not then you'd have to do a hard factory reset. Refer to this How to reset the password for the procedure on reseting the device, this type of reset will delete all of your data.

Is the battery an OEM battery? If It's not then that is the problem, many aftermarket batteries for MacBooks are not proper and could actually cause the board to short. Try a NVRAM reset as well. NVRAM Reset Guide

What is happening with the device Is that It's bootlooping, only thing you can continue to do try Is doing getting the device into the boot screen where you go to reset the device. Another thing that could be tried is new parts that could potentially cause the boot issue but most likely It's a motherboard issue with the device.

The bend and the liquid damage are big red flags itself. A slight bend could cause the fragile paths of the motherboard to break. Liquid could also cause big issues with the device not showing an image. What I would try is to clean the board with alcohol to rid of any corrosion then rinse the motherboard with distilled water and dish soap, dish soap leaves no residue. If you have a sonic cleaner I'd make use of it. As for the bend I'd try to mend back in place to see if can make reconnections with between the paths. Word of advice I would just shell out the extra to get a full device since a refurbished iPhone 6 with a warranty is around the same price as a motherboard from a reputable source. With a used motherboard from a broken device could be very problematic and could also be iCloud locked.

Here's a video disassembly of the A205 Toshiba A205 Hard Drive Replacement My advice is to just copy the contents of the other drive to the new one, grab an external SATA reader and navigate to your user folders in the drive and just extract the data you need. If you want to do a swap you can but I recommend running DriverPack after that to ensure you have the proper drivers to ensure you a stable system. Guides are often found with ease online, just write you computer manufacturer, the model number then hard drive replacement and you should get a plethora of options.

This error could be due to multiple issues, In short the error is a connection error that is telling you that there is a communication issue between the device and the PC. Here are some solution (1) Try a different cable, preferably an official Apple Lightning cable (2) Try a different USB port (3) Clean out the Lightning port, lint is sometimes in there not allowing a good connection, use a pick to clean it up (4) Try a new charging port, sometimes these port get worn and need replacement. This could be causing that error If all of these are tried and it still doesn't work unfortunately you have a motherboard issue which unfortunately would need a motherboard repair which most often is not cost effective. Hope this helps, best of hopes! iFixit iPhone 6 Lightning Connector Guide

Unfortunately at that point the motherboard on the device seems to have been shorted out. What you can try is cleaning the motherboard with some alcohol, and then spraying it with Deoxit. Since it smelled like something was burnt that motherboard maybe fried out. Some word of advice is that as soon as any electronic that has no sort of water resistance comes in contact with any liquid I would advice to immediately cut the power to it, not attempt to power it on, and clean up the internal components as stated in the directions above.

Your best option is getting a similar iPod same model number and switch the drive. At this point it sounds like a bad 30 pin port, you could attempt to replace it but it does involve quite an amount of soldering. Would just swap that drive, but my honest opinion is to also attempt to recover your songs because It's not long until that drive gives as well.

Check the terminals themselves, sometimes they may be loose and not gripping the posts. Also try cleaning the posts up just in case if any corrosion is causing the terminals to not contact correctly.