car won't start again 16v kr engine

[gwh18]

Car will not start again. Nothing comes from starting motor when ignition turned. It will start with jump pack. Battery has been checked and working at 75 percent capacity. Why if the battery fine would it start with jump pack? but not on just the battery? Could the wiring to starter motor be problem? It looks fine and clean. Or is the stater motor itself probably goosed? Any ideas? I've only got one leg at moment so it'll have to go to the garage anyway. Don't wanna look too ignorant in case I get the run around.

[Dee-GTI]

Forget the battery test and jus try it with a different battery on it. Also check the terminals/connections ETC.
has it been sat for a while?

[gwh18]

Connection to the starter motor was the problem, the wire was almost broken off. I'm assuming the extra boost the jump pack delivered must have deliverd enough power to turn starter over, but not enough juice with just the battery. new connecter and making the connection tighter on the spade with a crimping tool. No problems for 3 days. Touch wood. Glad i didn't go to a garage for that one. cheers folks