Fixing a Second Monitor that Flashes Black

Here’s a quick trouble-shooting tip.

After I purchased an M2 Max Mac Studio, my second monitor – an LG 4K HDR – starting flashing to black every few minutes. It would stay black for 5 seconds or so, then return to normal

The fix was simple, but took a while to figure out.

I replaced the Thunderbolt to HDMI cable with Thunderbolt to DisplayPort. DisplayPort is the native monitor protocol for Thunderbolt and, since I replaced the cable, the monitor has worked perfectly.

SIDE NOTE

Not all Thunderbolt cables are the same. It is ABSOLUTELY true that you get what you pay for. I made a point to buy a Belkin USB-C to DisplayPort 1.4 cable. ($30 US) It cost twice as much as the cheap knock-offs, but, unlike them, it also works.