Specifically, it won't change modes. Mine is an 8 mode. It wants to stay in the first mode, which is low. I want to use the second, which is high. I have disassembled it, cleaned the contacts, checked the solder joints, etc. but nothing helped. Once in a while it will change modes but then it goes back to being stuck.

Is there a driver I can put in it that will make it a one or two mode light? All I really need is high mode, but high/low would be nice.

Thanks in advance.