Hi there,
A little information about TV boxes in general.
Some BOX RK322x are really lowcost, so lowcost that the manufacturer to save a few cents do not populated certain component.
Here's an example of a box we recently received:
The motherboard is a R29_5G_LP3_V1.2_00523 and when we analyze the PCB we can see that the manufacturer hasn't installed the decoupling capacitors back of RK3228a CPU => This will make the box unstable.
Decoupling capacitors play a multiple role. Among other things, they act as local energy reservoirs, providing the chips with instantaneous high-frequency energy. As a result, they absorb high frequencies and limit noise propagation via power supplies between chips. The closer the ceramic capacitors are placed to the chips, the more efficient they will be, given the parasitic inductance of the tracks and vias.
The manufacturer had foreseen the installation of these decoupling capacitors... but didn't install them!
If your box is unstable, check that they are present: If they are not present I advise you (if it is still possible) to return this! ....
PoC.ng