How to repair it already check resistance and apparent are good

Hello Carlo Rodriguez, unfortunately so you say , did some measurement on the wrong scale, for example measure voltage on the OHMS scale, (RESISTANCE). Low quality multimeters do not usually have any type of protection against these errors, and the consequence is of being inoperable. For damage of the microprocessor, which has the form of a black drop in the IC Multimeters of good quality, usually perform a series of beeps when detecting an error of measurement or incorrect scale. What you can do is disconnect the buzer, and see which of the scales works correctly, obviously by performing comparisons with a multimeter that works correctly.