Hi John,
Eric has given you some good advice, I'm starting to like that guy :)
I would just add that iPad mini "no power" is commonly one of two things.
1.) True no power = the iPad is not recognized by iTunes when plugged into the computer. This can be several things, but the common one we're seeing a lot of is an inability for the iPad to charge due to 'non-Apple charger' damage to the charging ic inside the iPad. This chip is very sensitive to voltage fluctuation. If the chip is damaged, the mini can't charge, and will present as a dead mini. This is the most common cause of no power IF the mini has never been opened and not seen water.
2.) No display = the iPad is actually on, it is recognized by iTunes. There is just nothing on the screen. This rarely occurs in unopened minis, but it is extremely common in any mini that is under repair. The iPad mini backlight filter acts like a fuse for the backlight circuit. It is very sensitive to damage from a sudden spike in amperage that occurs when you disconnect the LCD flex from the mini motherboard without first disconnecting the battery.