Trying to upgrade to El Capitan

[fyrekrig]

Trying to install El Capitan on system already running Yosemite (Asrock G41M-VS3-2) on MBR partition
Have followed instructions as per text file enclosed. Everything seems OK.
When I try to boot with the USB drive I only get the blinking underscore.

Then installed Clover (Clover_v2.4k_r4458) on Yosemite installation and boot with USB stick present and try
to boot into USB. Starts OK but stops with spinning beach ball on grey background.

 

Then install Clover on USB and try to boot into USB but get only blinking underscore.

Any comment appreciated

elcapitan.txt