Background (can skip to "Priority')

I got my 1st n900 a couple months ago (perfect condition), flashed it with no dramas, installed CSSU and some apps. Bought a 2nd n900 with a scratched keypad and poor light distributing back-light.

The 1st phone I was installing something and finished the requirement to remove/disable something (I'm guessing, needed for boot?). I got distracted and forgot about completing the steps, phone worked fine until I rebooted it.
On 'power on' = white background, Nokia logo, turns to black (no dots), steady white LED the whole time until it powers down.

This is a while back, so that's what I remember. Have now done multiple attempts to flash, always ending up with it only recognizing for a second (it saying device RX-51, etc), then it's stuck on "Suitable USB device not found, waiting."

Tried majority of (wiki.maemo) on 32bit Mint and Vista, 64bit Mint and Win7 (with lib_32) using 2 different generic cables.
On Vista, "safety remove" icon would repeatedly appear for 2sec and disappear for 2sec.

There would be dark Nokia logo with USB icon for ages or might light up Nokia logo with USB, or reboot every 2mins.
I've only been trying Flasher-3.5, to install Vanilla (which must be done first?).


Priority
I'm starting to think the the USB port contacts are not sufficient.
One more try with a new liveCD of Linux/Mint 32bit but can't figure out how to continue from dialogue box when trying to install flasher .deb :


Can only seem to scroll. Have tried clicking 'Ok', typing O, OK, ok, y, yes. Hitting enter, Esc.
"Search engine" = no help

Ideas?