Is the option totally greyed out? Or do no WIFI networks show up when you turn it on? My first thought would be to back up your data then factory reset the device and see if that resolves the issue. If it is still having the issue after that, it may be the actual chip on the board of the phone malfunctioning. Getting another chip may prove to be non-cost-effective but more than likely your issue is software related, which a quick factory reset, or even a complete software reload should resolve the issue. Here are the instructions for factory reset on your tablet (this is for the 8.4" but it should be the same as yours): How to Samsung Galaxy Tab S 8.4 Factory Reset
I know exactly what you are talking about on this. Does the button actually push in and click, or does it appear to be jammed down in there? If it pushes in and is not working, it is most likely the button underneath that is soldered on the board has probably worked its way loose, or a circuit has gone out due to wear and tear, either way it would need to be resoldered, the worse case scenario is some kind of moisture or liquid damage. in which case it can still probably be fixed, its just a matter of what all is actually damaged. If it is physically jammed, the button underneath on the board may still be damaged and may need to be resoldered, but more than likely its just stuck and needs to be opened up and reseated. I hope this helps. Please let me know if you open it up and are still unsure of the cause, and possibly attach some pictures of what you see.
Hi Logesam, I apologize for not being too familiar with that device in particular. It appears to be very similar to the Galaxy S3 though. When you open it up is the charging port soldered on the main board, or is it a separate component attached by a ribbon cable? If it is truly similar to the S3, it may be easier to repair than you think.
It sounds like one of the rollers in the printer might be going bad, which would cause one side to feed faster or slower depending on which side it is. Typically when I see this in the field, it is caused by dust or something else caught in the gears, belt, or the roller itself. Pull that sucker apart and see what you can clean out. If that doesn't resolve it, you may need to find a way to recalibrate it. That user manual that Jayeff linked to you should have some information on that.
As David mentioned, it is possible that the pins that connect to the battery are bent or broken. Sometimes I have even seen a good amount of dust in them that makes it not connect well. I would attempt to do as David said and disconnect the battery and see if the computer turns on with just the power cord. Also, what model Samsung laptop do you have so I can research a few things for you that may help.