My 902 amp-clamp recently stopped working. Unit is a little over 9 months old. Voltage,temp,mfd,ect... still function fine. It just will not take an amp reading. I tried to do an online rma, but I do not have a serial number. I assume it may have been printed on a sticker on the back of the meter that has since worn off. Anybody know how i can get this repaired. I do have the receipt from purchase. I just don't have anything else. (Box,serial #,warranty card ect...) I should have registered it when i first got it.