Lenovo T460 laptop w/ Intel HD Graphics 520. Two identical external monitors: one on the HDMI output, one on the Mini-DisplayPort output with an MDP-to-HDMI dongle.
Problem: When I try to use all three displays (2x external + laptop), it works, but at least one of the externals will flicker intermittently (usually the one on the HDMI output). It's like there's noise on a sync signal or something. Parts of the screen will distort for like a fraction of a second at a time. Sometimes the monitor will blink off and on as though I've selected a different input (e.g. the OSD will show "HDMI" when the image comes back). Sometimes, when it's in a really bad mood, the flickering monitor will throw an error message saying it's being asked for a refresh rate that isn't what's set in software (e.g. 62 Hz instead of 60 Hz). Turning the affected monitor off and on again makes it okay for a moment, and then the problem resumes. Hugely disruptive.
The problem gets worse with sustained heavy HD access, or when there's an external USB HD attached. It also got slightly worse after we added RAM to the system.
When I only use two displays, the problem becomes almost nonexistent -- still there, but rare enough not to hurt my work. However, I did have one incident where the picture suddenly became all washed out and grainy until I rebooted.
Troubleshooting steps we've tried, in no particular order:
- Different monitors
- Every combo of output, cable, and monitor
- Different MDP-to-HDMI dongle
- MDP-to-VGA instead of MDP-to-HDMI
- Lower res on the laptop monitor
- Lower refresh rates on all monitors
- Different display scaling settings
- Different power outlets
- Different surge protectors
- Disabling unused system devices (WiFi, card reader, HDMI audio)
- Un-jumbling cables (to try to reduce EMI)
- Different laptop (exact same model)
No change from any of the above.
Any ideas? I have a couple more but I feel like I'm grasping at straws at this point.
Problem: When I try to use all three displays (2x external + laptop), it works, but at least one of the externals will flicker intermittently (usually the one on the HDMI output). It's like there's noise on a sync signal or something. Parts of the screen will distort for like a fraction of a second at a time. Sometimes the monitor will blink off and on as though I've selected a different input (e.g. the OSD will show "HDMI" when the image comes back). Sometimes, when it's in a really bad mood, the flickering monitor will throw an error message saying it's being asked for a refresh rate that isn't what's set in software (e.g. 62 Hz instead of 60 Hz). Turning the affected monitor off and on again makes it okay for a moment, and then the problem resumes. Hugely disruptive.
The problem gets worse with sustained heavy HD access, or when there's an external USB HD attached. It also got slightly worse after we added RAM to the system.
When I only use two displays, the problem becomes almost nonexistent -- still there, but rare enough not to hurt my work. However, I did have one incident where the picture suddenly became all washed out and grainy until I rebooted.
Troubleshooting steps we've tried, in no particular order:
- Different monitors
- Every combo of output, cable, and monitor
- Different MDP-to-HDMI dongle
- MDP-to-VGA instead of MDP-to-HDMI
- Lower res on the laptop monitor
- Lower refresh rates on all monitors
- Different display scaling settings
- Different power outlets
- Different surge protectors
- Disabling unused system devices (WiFi, card reader, HDMI audio)
- Un-jumbling cables (to try to reduce EMI)
- Different laptop (exact same model)
No change from any of the above.
Any ideas? I have a couple more but I feel like I'm grasping at straws at this point.
