I HAD A NEW M-6. ALL COINS ON TOP OF THE GROUND GAVE A REAL NICE SOLID HIT BACK AND FOURTH. I DUG EIGHT COINS ANYWHERE FROM 2-7 INCHES,AND EVERY HIT WAS SCRATCHY. CONNECTION WAS CHECKED ,IT'S GOOD. SENSITIVITY AND DISC WERE RAISED AND LOWERED. NO EFFECT.MACHINE WAS PROPERLY GROUND BALANCED.I THEN USED A FRIENDS DFX.SOLID HITS ON COINS ON TOP OF THE GROUND AND IN THE GROUND. HAS ANYONE ELSE HAD THIS PROBLEM WITH THE M-6. (BATTERYS WERE BRAND NEW) THANK YOU.