Screen blank after latest edid loading

[wichitakid71]

I have been messing with my monitor for a few weeks now trying to find the best combination of settings and modes to run groovy Mame, retroarch and my desktop.  My monitor is a Makvision 3125 tri-mode, so I have tried a number of different presets and settings.  My last attempt was to emulate a generic tri-sync monitor, but for whatever reason it was only entering settings for a dual sync monitor. I tried to undo this EDID setting and that’s when things went to pot.  Currently now the only thing I see with my Radeon card or my Intel onboard graphics is the boot screen (I flashed it to 15khz/31khz and it still appears to work).  Once the computer is done booting up, my screens go black. I am using a LCD monitor and my Makvision to test this out.  I know I must have set the resolution to something that my LCD can’t display, and for whatever reason my tri-mode is having trouble as well. I want to just restore this thing to prior settings and start all over again, but I can’t even see a window screen to get that done.

EDIT:  Card is a Radeon HD 8490, CPU Intel i5 4th gen, 8 GB ram.

I would appreciate any help, as this is really stopped my build in its tracks.  Thanks in advance.

Scott

[buttersoft]

The easiest thing to do would be reinstall windows.

Do you have a multimeter that can measure frequency/Hz? Put it on the h-sync or c-sync line and see what it reads.

[wichitakid71]

No on the multi meter. The OSD on the LCD says that my horizontal frequency is 48.4 KHz and the vertical frequency is 60.

[wichitakid71]

On the Makvision, after it boots up and I see the Dell logo (at what appears to be high tea), I hear the monitor click and the screen blinks out as if it is switching resolutions. It then remains black after that.

[wichitakid71]

Anticipating that I get my windows back to a workable resolution, what is the correct EDID/preset combo for my Makvision?  It has a switch that is supposed to control 15/24 kHz and 31 kHz.  Does that mean I have to choose one or the other?  It also seemed to work for awhile when I told Vmmaker that it was a std res only - arcade 15.7.  I’d like to find the optimal settings and leave it there. 

Thanks for the guidance.