Welcome to Photrio
@Luki !
the LED is not working anymore, but the thermostat and roller are working! Is there a way that i can test which capacitor need to be changed?.
It's unclear/uncertain and not necessarily very likely that a failed capacitor is the cause of a LED not working anymore.
What is this LED supposed to do? When should it light up?
Photo 1 is likely part of the low-voltage logic DC power supply and some filtering on the AC side; the round object top left of the photo is a bridge rectifier; there's likely a voltage regulator just below it (the one with the heatsink). If the machine mostly works OK then this section is likely just fine.
Photo 2 is what looks like a 8051-series microcontroller to me, which is the central 'brain' of the machine. Again, if the machine works fine for the most part, this chip and its directly associated circuitry is likely OK
Photo 3 shows a 4-port NAND chip; its specific function here is unclear.
None of this is directly usable in tracking down this specific defect. What is needed is a set of electrical schematics of the machine; on that basis and your fault description it may be possible to formulate a couple of hypotheses of what might be wrong, then you can do some selective tests/measurements to eliminate these one by one.
I ve changed the 4700nf capacitor
Which one? Did it help/make a difference?
Again, which one, where is it in the circuit and how does it relate to the LED?
Anyway, a schematic would be very helpful. Otherwise it'll be a matter of doing measurements around the LED and then seeing if the problem can be traced back, but lacking a schematic, it can be a lot of work and it requires some basic knowledge of electronics as well as a good deal of patience, and possibly partial disassembly of the machine so you can trace tracks also on the backside of the PCBs.