yeah, i would go with the bulbs first, one went on mine the other day and could only just see the left side of the display, or i thought one had gone, took them out to day, three bulbs to light the lcd display up, two blown, new ones in and good as new, couple of £ to fix if that, had spare bulbs in the garage. so if one or two have gone and it was down to the last one which could have been the middle bulb so display was lit up, then that blew, all display will be dark.