If it worked ok with friends battery...sounds like you need a battery.How old,etc? Have a voltmeter? Battery should be 12.6 minimum after charging,followed by quick usage to remove surface charge.
One of my vexilars went tits up last time I was metro icing. Found lots of useful troubleshooting info on vex page. Mine wouldn't read bottom well or pick up jig. Got it home,performed transducer test. All good,hmm.
Used it today, no issues with either transducer I used(robbed other unit).Battery is new this year. Bummer when broke stuff works...hope you get it fixed. Ill follow up on mine too.
Oh, hi Glenn
The temptation to quit will be greatest just before you are about to succeed