ac back lit display

hi everyone

i have a small problem with my ac controls. Every thing works as it should but the display is dark. You can just about see the letters and number if you look really close. My question is. Is there bulb that lights up the display and is it possible to change it or do i have to buy a replacement unit?

Is possible to replace lamps....do a search sure there is some information on this to hand!

Was a single bulb on mine....think I got it in without stripping much but was a fiddle.

The Hevac is easily removed and on the back are 4 (?) little bulbs to replace. another common fault is a loose wire on one of the plugs into the back that you need to unplug to get access to the back of the unit.