Cyberlight SV Power Issues

I am currently using 12 cyberlight cv's and in the last month I have had 5-6 have power problems where they just won't turn on. I have checked fuses but doesn't seem to be the problem. An electrician who had been work with them told me that lamp holder sensor may have gone bad or something in that region may have shorted but that doesn't seem to be the common problem. One cyberlight just needed a good hit in the dip switch area to turn back on. Any problem familiar with this problem and can lend some advice. Thank you.
Related