Not good news but it happens to the best of us at times, put it down to experience and get another unit
I wouldn't claim to be among the best of us, but I'm certainly in the 'been there, done that' category - fried an electronic battery charger (brand new, naturally - no point doing it on an old one!) by the simple expedient of plugging it in and carelessly letting the two crocodile clips touch each other.
Also some years ago cooked an alternator - again, brand new, only supplied by the garage about an hour earlier as a recon unit - by getting the wires the wrong way round.
Ah, happy days...
You youngsters can of course put it down to your lack of experience and youthful eagerness to get on with the job. When you get to my age, such rationale is denied... all that's left are 'senior moments'.... It's not a pretty sight