I was thinking chesterfield was a very popular style of furniture (chest-of-drawers) at one time so, I thought you were talking about the light over the dresser in the bedroom!
Anyway.....since both lights are in the slide, I would suspect a wiring issue under the slide. Open the slide, locate the 12v wiring and how it's routed. See if it appears to be pulled too tight when the slide is fully open. Then if you can safely, have someone close the slide while you watch the wiring to see if it kinks or gets "pinched" anywhere when the slide closes. If so, then that will give you a starting point to look for a break.