Article Number: 000131499
When a power-on system with the lid closed, the connected external monitor can not show on the boot process. For example: Post logo/ Bios Setup/F12 Boot menu/Bitlocker screen.
This is due to the AgS BIOS capabilities. Unfortunately, you need to connect a monitor with the exact native resolution of the internal LCD of the system. Otherwise, the screen will be blank.
How to check your internal LCD native resolution?
Power on the system, press F2 into the Bios Setup
Go to Overview -> DEVICES
LCD resolution |
FHD monitor (i.e. U2415 or HP2408h / 1920x1200) |
UHD monitor (Dell UP3216Q / 3840x2160) |
XPS 7390 2in1 FHD (1920x1200) |
Can display |
Can not display |
XPS 7390 2in1 UHD (3840x2400) |
Can not display |
Can not display |
LCD resolution |
FHD monitor (Dell P2418HZ / 1920x1080) |
UHD monitor (Dell UP3216Q / 3840x2160) |
XPS 7390 FHD (1920x1080) |
Can display |
Can not display |
XPS 7390 UHD (3840x2160) |
Can not display |
Can display |
The usual limitations with external monitors connected to docks attached to the system apply as well.
When using non-TBT dock in Pre-OS phase, system cannot output screen to external UHD monitor.
For example Monitor: UP3216Q(UHD) has a native resolution of 3840x2160 with 60Hz, the dock can only support 30Hz. On XPS 7390 with UHD LCD this monitor connected to a non-TBT dock such as WD15, WD19 there will be no video in preboot:
USB Type-C cable |
Single Display (maxdmun resolution) |
Dual Display (maxdmum resolution) |
Triple Display (maxdmun resolution) |
Quad Display (maxdmum resolution) |
Up to 10.8G of DisplayPort bandwidth(*2 DP lanes) |
mDP or HDMI: 4K * 2K @ 30Hz |
2 * FHD OR WUXGA(1920 * 1080 @ 60Hz)(1920 * 1200 @ 60Hz) |
3 * SXGA (1280 * 1024 @ 60Hz) |
Not supported |
Additionally please make sure to have the below BIOS and GFX driver versions installed for full OS support of external monitors:
XPS model |
Latest BIOS version/release day |
Latest Graphic driver version/release day |
XPS 13 7390 |
1.6.0, 07/31/2020 |
26.20.100.7985, 07/06/2020 |
XPS 13 7390 2in1 |
1.6.0, TBC |
26.20.100.8141, TBC |
If you found this article did not solve your issue. Please contact Dell Technical Support for further help.
XPS 13 7390 2-in-1, XPS 13 7390, XPS 13 9300
31 Mar 2021
4
Solution