Hi All,

I’m hoping for advice on an ongoing HDMI-IN resolution issue with my Dell OptiPlex 7770 All-In-One.

When I connect my Dell latitude 5420 laptop to the HDMI-IN port, the maximum available resolution is 1360 × 768.
1920 × 1080 is never offered, even though the internal LCD panel itself is Full HD.

What I have already tried

Hardware changes:

• Replaced the original motherboard with a new Revision A02 board (JWGHC)- Dell support recommended this however the ticket was closed and i can no longer re-open it or open a new case as the PC is now out of support. It was out of support when i raised the first ticket but i think they have changed the policy

BIOS:

• Updated to the latest BIOS
• No HDMI-IN or display-scaler options appear in BIOS

Cables & devices:

• Tested multiple HDMI cables - Other monitor picks up HD from same cables

• Tested multiple source devices (Windows 11 laptop, others - Same result every time: HDMI-IN capped at 1360 × 768

Windows:

• Tested on Windows 10 and Windows 11

• Installed - Dell On-Screen Display Application
• Updated all the recommended drivers
• Also tried active USB-C to HDMI adapter (UGREEN) but still limited to 1360 × 768 - However this failed on the old motherboard not tried on the newly installed one - Rev 2 

Abit baffled on what to try next, i feel like i might be missing something as i really thought the Rev02 motherboard would fix the issue. Any help appreciated, thanks