Aerotechi

Good morning, The warnings on my DIS/LCD eg low fuel, washer fluid etc appear but the yellow back light doesn’t light up (sometimes it does if a cold morning or will flicker) so I’m thinking there’s a loose solder joint somewhere. Could anybody tell me what puts the yellow on or a schematic? So I can potentially re solder or replace the component myself. For clarity the symbol is being generated as you can see the “hole in the black” just 99% of the time not filled in in yellow. And the section works fine in white. I had the garage look last time it was in who said 1 of the 4 somethings had popped but I’ve forgotten what it was. Many thanks in advance.