I bought A battery charger 6 months ago, i went to use it one day, and it was Humming and vibrating very loud, and would get hot , before all this it worked perfectly, it makes me mad when you pay good money, and they want to charge you more money to fix a problem on a item that was only used maybe a dozen times, well i get tired of that BS and i always try and figure out the problem myself, $11 diodes and a $1 to ship them to me, and now i have spare diodes incase the problem happens again and i can repair it myself without loss of time and money, im sure a lot of people have this simple problem, i hope this might help you solve your Battery charger problems as well.