IBM 5162  -  Basics, for 5162 beginners

Besides "XT Model 286", IBM has also referred to the IBM 5162 as the "XT/286".   (Example)
Although the model name has "XT" in it, the IBM 5162 is an AT-class computer, not an XT-class one.
To quote the 'Upgrading & Repairing PCs' book, "This model may look like an XT, but under the skin, it's all AT !".
The decision to give the impression that the machine is XT-class, would have been a marketing one.
SETUP (BIOS configuration) ("CMOS SETUP") cannot be accessed via keyboard.  Methods for SETUP are at here.
The floppy drive supplied by IBM is a 1.2M one.  Click here to read about a problem caused writing to 360K floppies in that drive.
The IBM 5162 fully supports 1.44M drives and diskettes.  Attach one, adjust the SETUP, and 'away you go'.
The IBM 5162 was released after the IBM 5170 (IBM AT).  See here.
The general performance of the IBM 5162 motherboard is between that of a 6 MHz IBM 5170 and an 8 MHz one.
   - IBM 5170, 6 Mhz, one wait state RAM
   - IBM 5162, 6 Mhz, zero wait state RAM
   - IBM 5170, 8 Mhz, one wait state RAM
By the way.  Claims that IBM created the IBM 5162 just so that it could use up stocks of IBM 5160 (IBM XT) cases are pure speculation.  It seems unlikely to me, considering the cost of system development (including technical documentation), administration, testing, and marketing.
Aged tantalum capacitors are known to explode.  That has happened to me many times, particularly when I have acquired something that has not been powered on in years.  If the motherboard, or expansion cards, are exposed to your face when you power them on, then consider wearing glasses of some sort.  More information at here.