Error connecting the port is disconnected Mtk

I go to connect my phone mtk tab off and for a moment I get the vcom port or preloader but in less than 2 seconds disappears and the phone is turned on, I stuck on the logo but not recognized in any way ...



I feel the same with several phones



guess is driver issue but I could not solve



PD and try in another pc and is same ...my drivers are at page sigma

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