He bought it with a broken cable, it is a not-for-resale unit.

at this point, I think the best way is to solder a new cable (like a floppy drive cable) to the transition between the gray ribbon cable and the orange flat-flex, then solder that cable to CN1 on the display and on the inverter

Also, how do I test the logic board?, tried hooking up my bench power supply to the main battery, together with a brand new 9v secondary battery, but it shows no life...

the hard drive's rubber gasket is melted, so I am also looking for a cable adapter (or a good diagram)

Is the logic Board a Backlit or a Non-backlit model?