Problem The light on board no longer works


Hi. I also have a problem if someone can help me. I have an audi a4 b5 from '95 and I opened the dashboard to replace the heat radiator. I put it back and I have a problem with the light on the board. The tachometer no longer lights up to 3000 revolutions and the mileage at the number of km. Is it a problem with the LEDs or something?? Do I have to buy new watches? All plugs are inserted, everything is ok. but after I finished the whole job, in the evening when I looked at the board, I could no longer see the above mentioned.

Thanks a lot.