HELP! Keep getting "No Sync" Signal on Wacom Cintiq 12wx

I bought a VGA adapter for my Cintiq so I could use a better resolution for it. Everything worked until my Macbook Pro asked me to install some upgrades, and then after that, it just wouldn't work and I kept getting a "No Sync" error message. Did I do something wrong? Like seriously, no matter what, this thing keeps giving me some sort of error signal. First it was "Signal out of range" and I tried to fix that, and now it won't turn on. I'm starting to pull my hair out. I really, really really am begging all of you, to please help me. I've turned the computer on, off, unplugged everything and then replugged it. I've switched from DVI to VGA. I'm going totally mad, I need your help. I have an ungodly amount of work and I just bought this thing. Wacom's closed for the whole weekend till Monday due to the Holidays. PLEASE help me, PLEASE.

you can have a try with HDMI Cable , and does you connect the cintiq 12wx to a power .

I have a wacom cintiq 12WX for five years , but now I upgrade to XP-Pen Artist 15.6 Pro Drawing Tablet Monitor . because A Wacom Cintiq is really too expensive for my budget so I thought XP-Pen Artist 15.6 Pro was a good option.

my Artist 15.6 Pro Display Monitor has a 15.6 inch ips screen , 1920 x 1080 (16:9) FHD resolution , 88% of NTSC is roughly equivalent to 120% of the sRGB color gamut. 5080 LpI.

the stylus p05r come with tablet was battery-free and wireless . it has 8192 levels of pen pressure . support pen tilt function . I can now use pen pressure and pen tilt in photoshop and corel painter .

Welcome to the forum. The thread you joined is from 2010, just over 8 years old, so don't expect too much from the original posters.