Galaxy Tab 4 (SM-T530NU) "gapps" and "Play Services" stopped

[exapplerep]

Have a Galaxy Tab4 that has been factory reset (using both the menu item and booting into recovery mode "wipe data/factory reset"). When it boots, I get the same few messages repeatedly: "com.google.process.gapps has stopped", and "Google Play Services has stopped". It never stops repeating. It happens whether it's connected to the Internet via WiFi or not.

I imagine I would need to re-flash the firmware (5.0.2) for the US model ("XAR"). I'm downloading it now but haven't a clue how to get it into the unit to replace the existing firmware.

I do know how to get it to boot into recovery mode but that's my limit. I did try installing Odin and the Samsung phone drivers but Odin shows nothing connected regardless of how I boot the Samsung (recovery or normal). (The Samsung is connected via USB2.)

So I'm at the end of my rope here. I do see (in recovery boot) something about USB and ADB so I guess that may be the solution somehow but I have no clue what to do now. If there's a step-by-step guide for this that assumes I know nothing, I would greatly appreciate a link. Alternatively, if you know how to fix this and wouldn't mind a little dialog in the forum, I'll monitor this thread.

Thanks very much!

Barry