Broken battery contacts? I am not sure why this happens, perhaps some users are a bit rough when taking off and putting on the battery. Could be that the contacts are damaged when the radios are in transit with no battery attached. Whatever the reason I will replace the contacts on many makes and models of two-way radio handsets. A small percentage cannot be replaced as the solder pad on the printed circuit board come off with the contact. I must say this does not happen very often though.
I also replace the contacts on DP3400's, DP3600's and many other makes and models. DP3400 and DP3600 on/off and channel switches replaced.
Download the "Repair Request" form here