LCD not displaying image intermittently

Ok, I'm almost at my wits end with this Dell d630.

I replaced the motherboard with a refurbished one because the LCD 90% of the time wouldn't display an image. Occasionally it would, but then would flick out at a random interval. The backlight is fine and the computer is running fine, but there's no image when the problem is occurring.  It's NOT the problem where the screen goes dark, the image just isn't displaying at all.  The backlight still on and fine.

After replacing the motherboard, it worked great for a few days but then the first time I tried watching a video it flicked a couple times and then went out. Upon reboot, no video, but it popped back in after a minute. At one point the LCD seemed to be 'pulsing' and then flick in and out. But usually it's either on or out.

Now either I got another bad motherboard (supposedly refurbed by Dell, but graphics problems have plagued this model GPU). It's not displaying any anomalies that I've seen.

Possibly the connector coming from the LCD?

Are there cases where the inverter can go, or start to go, but the backlight is still on and working fine?

Any other guesses?

Thanks!