Need advice on re-flashing my broken Tronsmart cx919

[SarasotaSlim]

Ok, I'm a first-posting newbie here.

I bought a Tronsmart cx919 about six months ago, via Amazon, (iirc).

It is black case and says

"TRONSMART"
"WiFi Mini PC and TV Dongle"

in lower right corner of top.

Also on the top, at left side, it has that tilted top-half-picture of green Android-logo.
and says "Quad Core" above that logo.

[On the bottom, has a silver oval sticker showing "8G | 2G" on top line and
"Quad" on 2nd line. ]

[It has a single black antenna that rotates up, located 75% of way to the left
on the back edge. ]

Long story short, it worked ok, hooked to my living room TV. I operate
it via a wireless keyboard and wireless mouse. I probably booted it up and'
used it on at least a dozen sessions, and it was working fine. Then, I got
working on other projects, and didn't use it for the last few months.

The other day, I hooked it up, and tried to boot it
and it is acting weird during bootup. I see the spinning arrows around the
Android-logo for 10 seconds or so, and it usually makes it as far as starting
to show the normal homescreen/desktop layout, but then bails-out, flashes,
and is back trying to reboot, again showing the spinning arrows around the Android logo.

Sigh. So, now I'm thinking that I'll need to learn re-flash it, to (try to) get
it working again.

At the Tronsmart website, I find what they consider the best firmware
to use, which is named:
"Tronsmart CX-919_4.2_20140725.zip"
and when I unzip that, I get a single file named:
"Tronsmart CX-919_4.2_20140725.img"

[but, alas, I can find no instructions at their site, for how one would re-flash
that image.]

Great. So, can someone point me to the additional tools and instructions
on how to proceed to try to re-flash this image back into the device?

[ I'm quite geeky, Android-wise, using my Nexus-7 tablet. So, I get how to
attach it to my Windows-laptop's USB port, as I've learned to download
APK-files and media-files to the tablet, am assuming I'll be doing something
similar to re-flash this CX-919. Also, I've run various Linux (Debian-based)
distros, which is helping me understand what's being said here.]

EDIT: Oh, I am certainly willing, as an alternative, to try using some OTHER
firmware (e.g. Finless)...I found a ref on YouTube, to 1.6b, so I've downloaded
that but haven't examined it yet. So, Bob (aka Finless)...if you read this, please
bring me up to speed on what you'd suggest.

What do I do next?

TIA...
SarasotaSlim

[SarasotaSlim]

Resolved the boot issue: Ok, it was a "lack of good power"

Ok, after googling around and reading stuff, it finally dawned on me, what
people are meaning to say, regarding "use a RELIABLE USB-hub"!

The ISSUE is that all TV's USB-ports are NOT created equal. Some of them
will NOT supply enough power (amps) or steady-enough power, or whatever!

Long story short...once I quit using the damn USB port on this new (Panasonic)
TV and went straight to using a USB-block (e.g. the one that comes with
Chromecasts and cellphones, etc), this TV-dongle now boots up reliably and
stays up! (DUH! Live and learn!)

Voila...booted up nicely, so I'm back in business!

So, we can consider this thread solved. (I'll come back later, if I decide to
try one of these newer firmwares...for curiosity reasons, etc.) For now,
I'll stick with the existing firmware, since it's now 'firm'.

Thanks for listening.