Error code h5 is equivalent to ipm protection (loss of synchronization protection and high voltage protection in compressor phase). The first thing you will have to check the consumption ... maybe something is in poor condition (capacitors) if it is three-phase, check what feeds the motor ..... look at the motor consumption with amperometric clamp and compare it with what it says in the sign of it! The second check that the condenser is not dirty, dirty filter, very high ambient temperature or some strangulated pipe; This code can also give you for low supply voltage, check that the power cables are tight and in good condition. Finally test the compressor directly from the terminal board, if it starts you must take the plate to repair or replace. Do all of the above and leave the last plate repair or replacement.