"After loging in my screen goes black and unresponsive."に関する回答I had similar problem and it was very frustrating. After updating latest os versionon on my MacBook Pro mid 2010 and reboot screen backlight didn’t come on again. After turn off and on grey screen and Apple logo as usual. Was able to put password and afterwards screen turned dark. There was something on the screen but barely visible. Keyboard and trackpad didn’t respond. Tried hard reset and some other things but nothing seemed to help. After closing the MacBook and reopen it now works normal. Really strange.
"Up arrow key not working after cleaning"に関する回答I know that is not really a answer to your question but i recommend to use a barely wet cloth to gently remove dirt from the keyboard, only water no cleaners or other fancy stuff.
"head phone jack stuck"に関する回答Yes you can replace the headphone jack but its one piece together with the hold switch. And this iPod model is quite hard to open. See here: iPod Classic Headphone Jack & Hold Switch Replacement
"How to install dual hard drives, solid state drive and Serial ATA?"に関する回答maybe this helps: How to add one or two SSDs without interfering with fan issues