Does an external monitor work when the cable is disconnected on a laptop?

Question

Iron

Netbook msi u135dx, win7 began to periodically turn off the screen, suspected a cable malfunction. I connected an external monitor with difficulty, I had to dig into the settings, but then the monitor worked well through the wga cable. the led matrix. Of course, I disassembled it with the battery removed, after grounding. At the same time, I completely removed the board (hdd, cooler), cleaned everything, changed the thermal paste to the CPU, assembled everything. I didn’t see the cable, I wanted to connect it through an external monitor. I also noticed that after pressing the power button, the sleep mode indicator immediately lights up and lights up constantly, and the hdd indicator flashes periodically. Questions:
1. In principle, should a signal go to an external monitor when the cable is removed?
2.After disassembling the laptop, can the settings of the external monitor fail?
3. How to turn off sleep mode? I tried to remove the battery with a long press of the power button, the combination Fn + F2, F10, F12, contr + alt + delete + enter, turning it on through the BIOS, nothing helps, the indicator is on. By the way, it was generally disabled in settings, there was a jackdaw, never, And how is the sleep mode implemented when the lid is closed, maybe due to the fact that the matrix was removed?

Answer 1

1. Must.
2. They can.
3. You may have a closed lid sensor. Try reassembling the laptop and keeping the lid open, or find a sensor and make it think the lid is open.
Regarding the external monitor monitor - in Windows 10 (and possibly earlier), the Win + P combination opens the panel on the side and by moving up and down you can select items by pressing Enter.
Try it blind. In theory, Win + P, down arrow, Enter should be enough

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