Door Entry DS-K1104M stopped reading cards?

[Munu8744]

I have a DS-K1104M mifare card reader. It is connected to access control DS-K2604T. They are connected with Rs-232. Up until now i didnt have an issue. Today it stopped working. The blue light is blinking normally. The access box shows it is connected, however when I swipe there is no event registered on ivms. It is as if the card reading functionality is broken. Is this possible?

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