The only thing Dr. Google revealed was some monitors having a "theft mode" than needed some strange front panel button presses to reset.
Try connecting the Raspberry to some other TV/monitor.
Microprocessor, Raspberry Pi & Arduino Hacker
Mainframe database troubleshooter
2012-18: 1B*5, 2B*2, B+, A+, Z, ZW, 3Bs*3, 3B+
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