<< Solved >> GT-210 / High Sierra: No signal from HDMI port after boot-screen

[manav]

Hi,
I have a working Hackintosh which I have been using since February. I have it dual-booted with Windows 10. Here are some of the specs:
OS: High Sierra/Windows 10
RAM: 16 GB DDR3
Processor: i3-3220
Motherboard: Gigabyte H61M-s
GPU: GT-210
You can find all the other details here in my full installation guide.

Details about the monitors being used:
Acer P166HQL: 1366x768 / VGA only ; I'll be referring to this as "VGA Monitor"
Dell U2415: 1920x1200 / HDMI, DP, mDP ; I'll be referring to this as "HDMI Monitor"

The system has a GT-210 which has VGA, DVI and HDMI out ports.
Since the beginning, I had been using it with the old VGA monitor which worked right out of the box. Had to "Inject Nvidia" in order to get the monitor working at native resolution. Everything was perfect until today. I bought a new Dell U2415 which has HDMI, DP and mDP in ports. I connected the Dell monitor through HDMI, while leaving the older Acer monitor connected to VGA. I booted into Windows 10 and had a perfectly working dual-monitor setup. Both the monitors work flawlessly at their native resolutions.
But when I tried to boot up macOS, this is where the problem begins. I'm able to reach the boot screen. As you all might know, when the macOS/Hackintosh boot-up process is almost complete, there's a point when the screen resolution is changed. This is the point where both my monitors stop receiving any signal.

I had to force shut down the system. Then, I disconnected the Dell's HDMI cable from the GPU and left the old VGA monitor connected. Tried booting up again and it booted up just fine. The system was booted up, and as soon as I connected the HDMI cable back to the GPU, it still didn't work and the older monitor immediately stopped receiving any signal. Tried disconnecting the HDMI cable but the older monitor still didn't receive any signal. Had to force shut down the system again. I then disconnected the VGA monitor and connected the HDMI monitor back.
I went to the Clover bootloader options and booted with "nv_disable=1" and the system booted up. But the resolution was odd. The system was unable to identify the monitor and its native resolution. So I'm unable to use the newer monitor without "nv_disable=1".
I also tried booting up after disabling nvidia injection, but the system goes into bootloops with this.


To summarize:

• If booted up with only the VGA monitor connected, everything works fine.
• If booted up with only the HDMI monitor connected, it doesn't receive any signal after boot screen. However, it works when booted using "nv_disable=1" but the resolution is odd, all the UI appears glitchy and the monitor is unidentifiable.
• If booted up with both the monitors connected, none of them receive signal after boot screen.
• If booted up successfully with only the VGA monitor connected, and the HDMI monitor is connected afterwards, the VGA monitor stops receiving the signal. In other words, the HDMI monitor doesn't receive any signal, nor does it let the VGA monitor receive the signal.

Another thing that I'd like to mention is whenever I have the HDMI monitor connected (without signal) and I try to remote control the Hackintosh using Chrome Remote Desktop (which mirrors the computer screen to your phone over the internet), I noticed that the all of the interface was glitchy. There was a white block behind the cursor. And all the menus and application windows just appear blank, whether it be settings, "About" screen, or safari.
I've read many similar threads but can't find a solution that works for me.
I just can't get the new HDMI monitor to work at its native resolution, let alone having a dual-monitor setup.

 

[manav]

I'm attaching my EFI folder here, if required. I'd be really grateful if anyone can help me out.

 

[manav]

UPDATE: So I was finally able to get the HDMI Monitor to work. I did the following:

• Opened up BIOS
• Under "BIOS Features", I changed the "Windows 8 Features" setting from "Other OS" to "Windows 8 WHQL".
• This unlocked "CSM Support" setting, which I set to "Always"

But now, I can't get the VGA monitor to work. Now, the situation is as follows:

• If booted up with only the HDMI monitor (Dell U2415) connected, the system boots up fine. macOS is able to identify the monitor's name and the monitor is working at its native resolution.
• If the VGA monitor is connected while the system is booted up, it doesn't receive any signal, though the HDMI monitor keeps working.
• If booted up with both the HDMI and VGA monitors connected, I get the same problem of both of the monitors not receiving any signal after the boot screen.

So therefore, I am still unable to have a dual-monitor setup. At least, the new monitor is working now, though it's a little bit inconvenient to disconnect the VGA cable every-time I want to use my Hackintosh.