Rockinar, the failure to start is either a
power supply issue or a refrigerant problem. You can easily check the
power supply by monitoring the DC voltage at the MDM's + and - terminals. (top two) with a multi-meter. If there is no problem with the power supply (voltage drop) then get the system evacuated, a new filter dryer fitted and re-gassed with R134a.
Not knowing the
history you have to assume some dodgy work could have contaminated the system and only a complete clean up will resolve that.