Default Help with Acer liquid S2/S520 flashing

Hi folks,

So after successfully rooting thanks to this post by Shreps, and updating with official Acer OTA update my new Acer Liquid S2 is now crashing every time I start it. Before the update everything worked fine with root.

I want to reflash it with the older version or even a custom rom but there is now no bootload/boot menu, just a fastload screen when I try to access the boot menu.

Can anyone please assist with this?

Any help would really be appreciated.
Many thanks!