No lighting of the dashboard at times due to trivial reasons. Maybe the connector pins just rust, scientifically speaking, are corroded. So visually check the condition of the wiring and the connectors of the chain, and then proceed to a more detailed inspection of all components.
The reason that the dashboard ceased to burn, could be a blown light bulbs (LEDs) and fuses. You may need to replace the relay or fuse.
When replacing light bulbs need to pick up a light bulb the same power that burned, otherwise the panel will be lit unevenly. To put a more powerful bulb is burned is not recommended, because it can melt plastic. Please note that if you have previously installed the "non-native" elements, and they could cause breakage now.
To find a more serious fault, you will need to apply diagnostic instruments, for example, a circuit tester or voltmeter.
Perhaps the reason is a blown fuse or relay. To replace them you need to understand their location. As a rule, they are located in the mounting blocks located in the passenger compartment under the instrument panel on the right side.
Do not replace fuses self-made jumpers or fuse for different current, this is very dangerous and can cause damage to electrical appliances and even cause a fire. To extract a fuse use the special plastic tweezers.