D4dmx-md5 stop working. No schematic. Problem came slowly then it stop working. Get a bit of light on the led display Maybe a power supply problem

You did not post enough information on symptoms to get a good answer. However, the most common problem with these dimmer packs is a failure of the sermiconductor that controls the amount of power going out to the attached light. In the D4DMX, there are 4 such, of a type class of semiconductors known as "triac", part industry part BT16A (the "A" is important, as it indicates an internally insulated mounting/heatsink tab). When this part fails, the output channel stops working, but the other 3 channels continue to work. Altho rarer, it is possible for multiple channel triacs to fail. The failure of a triac is typically due to (1) attached bulb filament failure (in a manner where a filament fragment shorts across the mounting posts), (2) channel overload (eg, plugging in a greater load (significantly greater wattage) than the D4DMX channel is rated for), (3) AC power line surge. You need to be a trained & experienced ELECTRONICS (ie, NOT electrician) to accomplish this repair safely & satisfactorily, and it involves soldering & specialized test equipment.
The D4DMX series is also known for failures of its control cable interface circuitry, both for Microplex and DMX. Microplex failures is more common, as that type of interface is more sensitive to induced noise from nearby AC wiring, radio signals, and standing wave reflections from varying lengths of control cabling. DMX uses a differential control signal interface, which makes it much more immune to induced noise, but it operates at a lower signal voltage which makes it more sensitive to accidental application of improper voltages on the control cable...which often happens when someone connects the DMX ports on the dimmer pack to a Microplex connector on another pack or the control console. One clue is to look at the single tiny LED right next to the control cable connectors; if it's lit green, then the Microplex signal is detected, if it's lit red the DMX signal is detected, if it's not lit at all (off) then no signal is detected which just may be an interface circuit failure. Such problems are a bit more challenging to troubleshoot internally, and requires a proper oscilloscope or logic analyzer.
In both of the above cases, you will see what may look normal on the LED display, but the dimmer pack will not function properly.
You should describe more symptoms of your problem, such as: Are all light output channels not working, or just 1 or 2? Which control interface are your using (Microplex or DMX)? What is your LED display saying? What are the present settings programmed into your D4DMX? Are any other working channels responding to the control console normally? What is the total length your control cables, including those between serial connected ("daisy-chained") multiple D4DMX dimmer packs? Do you have any non-D4DMX dimmers in the control chain, and are they all connected using the same type of control interface (Microplex or DMX)?