The cooling process of the devices is a big challenge in the electronic industry, and most of the process units (graphical are central) experience defects under harsh temperature conditions, so dissipating generated heat under various working conditions should seriously be studied. This study investigates the magnetohydrodynamics of hybrid-ferro nanofluids in the presence of hydrophobic surfaces in a micro-heat sink. To scrutinize this study, a Finite Volume Method (FVM is applied. The ferro nanofluid includes water as base fluid and Multiwall Carbon Nanotubes (MWCNTs) and Fe3O4 as nano-additives, which are used in three concentrations (0, 1 and 3%). The other parameters such as Reynold number (5-120), Hartmann number (magnitude of the magnetic field from 0 to 6) and hydrophobicity of surfaces are considered to be scrutinized for their impacts on heat transfer and hydraulic variables as well as entropy generation ones. The outcomes indicate that increasing the level of hydrophobicity in surfaces leads to improve heat exchange and reduces the pressure drop simultaneously. Likewise, it decreases the frictional and thermal types of entropy generations. Intensifying the magnitude of the magnetic field enhances the heat exchange as much as the pressure drop. In the same result, it can decrease the thermal term in entropy generation equations for the fluid, but it increases the frictional one and adds a new term named magnetic entropy generation. Incrementing Reynolds number improves the convection heat transfer parameters although it intensifies the pressure drop in the length of the channel. Also, the thermal and frictional kinds of entropy generation decrease and increase with increasing the flow rate (Reynold number).