How to fix No HDMI signal on Mac Studio and Dell Monitor

Given that you've already attempted multiple cables without success, it's possible that the issue lies with either the Mac Studio or the Dell monitor itself. Here are a few steps you can take to further diagnose and potentially resolve the issue:

Firstly, try connecting your Mac Studio to a different monitor or TV using the same HDMI cable. This will help determine whether the problem is specific to the Dell monitor or if it's a broader issue with the Mac Studio's HDMI output.

If the issue persists with a different monitor or TV, it suggests a potential problem with the HDMI output on your Mac Studio. In this case, you may need to reset the NVRAM (non-volatile random-access memory) on your Mac Studio, which can sometimes resolve display-related issues. To do this, shut down your Mac Studio, then turn it back on and immediately press and hold the Option + Command + P + R keys until you hear the startup sound for the second time. Release the keys and allow your Mac Studio to boot up normally.

If the problem only occurs with the Dell monitor, it's worth checking for any firmware updates or compatibility issues between the monitor and the Mac Studio. Visit the Dell support website and ensure that your monitor's firmware is up to date. Additionally, try connecting the monitor to a different device (such as another computer or game console) to see if the issue persists. This can help determine whether the problem is specific to the Mac Studio or if it's related to the monitor itself.

If you're still unable to resolve the issue after trying these steps, consider reaching out to Official Apple Support for further assistance. They may be able to provide additional troubleshooting steps or advise on potential hardware repairs if necessary. Additionally, contacting Dell Support for assistance with the monitor could also be beneficial in resolving the issue.

What model is the Dell monitor and what other video input connections does it offer...?

Mac's do not like long cheap poorly made HDMI cables.

If you have tested a short High Speed Premium Certified HDMI cable.

https://www.amazon.com/Ultra-Highwings-48Gbps-Braided-Cable-4K/dp/B08NX5CZTF/ref=sr_1_4?th=1

Then it is time to test another connection method like a USB-C to HDMI adapter

USB-C Digital AV Multiport Adapter - Apple

or.. USB-C to DisplayPort cable if the Dell supports DisplayPort input.

https://www.amazon.com/dp/B0CSJQY34N/ref=sspa_dk_detail_4?th=1

For more info on connecting display(s), see > Connect a display to Mac Studio - Apple Support

There are lots of HDMI cable around that simply can not support today's high resolution displays. Substituting a different cable is a check against broken wires in the cable, but not against suitability for the task at hand.

HDMI cables you want for HDMI-only Displays (higher resolutions than 720p TV sets) are marked as Certified with an anti-counterfeiting tag and are labeled:

"Premium High Speed HDMI cable" or that + "with Ethernet" --OR--

"Ultra High Speed HDMI cable" or that + "48G"

Cables with No Certification tags are good for your standard 720p TV set, and not much more.

HDMI was invented for HD TV sets. it works great at its original resolution of 720i or 720p. At higher resolutions, it quickly develops issues that are complex to solve, and the cables and adapters required to solve are NOT intuitive.