Windows 10: my second monitor goes off when I connect power to my laptop

I have KVM Switch through which I have connected 1 27 inch monitor/keyboard/mouse to two laptops. It works fine when Laptop is on battery. but as soon as I connect power, 2nd monitor does not detect input and goes to standby. I am still able to use keyboard and mouse. I am using duplicate these displays setting. if I use extend display setting, then same issue happens. Monitor stops getting input and goes on standby.

:)

 

Second monitor connected to DVI on laptop will not power up

I recently bought 2 new windows 10 laptops (one dell, one HP) and am having problems on both when using second monitor.

This monitor worked fine on my old laptop with windows 7, the monitor went on and off with computer power and sleep.

With windows 10 the monitor power behavior is unpredictable, but mostly will come on for a few seconds, then go off, windows makes the 'device connect' the 'device disconnect' sounds. I have the same problem with both the laptops. It takes several frustrating
attempts to get the second monitor to stay powered up and connected. This has to be done every time the laptops wake.

Help, Please. I have checked drivers (up to date) and power settings (always on).

 

Second monitor powers on and off every few seconds

I connected an LG IPS234 monitor to my wife's HP laptop using an HDMI conversion cable. When I first connected it it worked fine. But after my wife powered down and up the next day it stopped working and hasn't worked since. The power goes on and off every few seconds. Right before the power goes off the correct screen image flashes. So the laptop knows the monitor is there. I've set the power management for both devices to never sleep. I changed the driver to LG's but that didn't fix it. Another monitor works fine using the same cable when connected to the laptop. The monitor does the same thing when connected to my computer.
Looks like the monitor is the problem?

Laptop is an HP ProBook 6570b 64 bit, 16 gig memory, Intel Core i5-3360M processor with Intel graphics adapter.

 

Using 2nd Monitor with Laptop and Goes Into Sleep Mode

Hi Charlie,

If your second monitor goes in to Sleep mode after connecting it to your laptop, it could be that some settings of the Power Options in Windows 10 are incorrectly configured. We recommend that you restore all power settings to default and see if the second
monitor still goes to Sleep after connecting it. Here's how to restore the power settings to default:

• Press the Windows logo key + I to open the
  Settings app.
• From Settings, select System > Power & sleep, then select
  Additional power settings.
• From the Power Options dialog box, select Choose when to turn off the display, then select
  Restore default settings for this plan.

After setting it to default, observe if the issue persists. If it does, kindly connect the second monitor to another computer and see the problem is observed. Also, kindly use a different HDMI cable to rule out the possibility of a faulty cable.

We look forward to an update from you.