I had a hard way. But this informations I have collected:
Q: All *.bin are down. How can I find (extract) the bin file
A: Download the build you are searching for from the acerside (its a zip-file with an exe in it) , install it.
Don't close the setup wizard
open: C:\Program Files\Acer Inc\Acer LiquidMT Tool\acer_EuuDownload_Tool\acer_MergedOSFile
that is the bin file you are looking for.
My MT120S was bricked and I have installed the only bin a could find, with was an GEN2 (for Asia), now am not able to flash a other bin, because it doesn´t except a GEN1.bin.
USB istn´t responding (so no ADB, AcerDownloadTool and no updateingtool is working) I only can use SD Card-mode.
In SD Card Mode the S120
-checks the language (Gen1 or Gen2) so if you have already installed one of them>no chance
-If you use a downgrade (4.001 installed, back to eg. 3.00x) you get an invalid file massage
-If you use an upgrade (4.001 installed, up to 4.013) you get: "wrong MD5 checksum...are you a hacker"
So. If YOU only see the "Acer"-logo and you aren´t able to boot or get into the recovery.
Go to "SD Card mode" (Vol- and Cam and Power)
Insert a SD Card and copy the !right! "...Gen1.bin" for Europe/US (or "....Gen2.bin") for Asia to
the following folder (SdCard:\)acer_ug/acer_xx