Mac Mini M2 wifi issues

Ken Shimabukuro,

The Ugreen HDMI cable with model number 20276.

The Wi-Fi used is dual-band, supporting both 2.4GHz and 5GHz frequencies, and it uses the same SSID. The devices automatically switch between the two frequencies, and it is not possible to separate them and use different SSIDs. The Wi-Fi device model is Netgear Orbi AX4200 WiFi 6 Mesh (RBK752). Checking the connection list, the Mac mini m2 is connected using the 5GHz channel.

For those with M2 Pro Mac mini Wi-Fi issues, please report what channel (1-14, 32-177, 1-233) and frequency (2.4GHz, 5GHz, 6GHz) your Mac mini is connected to and if you're currently experiencing problems. Thanks!

I've not been able to find any information on the Ugreen HDMI cable with model number 20276. At any time did you read anywhere that it was shielded? And it would be giving off 2.4GHz EMI not 5GHz, so I wonder why grounding your HDMI plug made such a difference. Unless 2.4GHz electromagnetic interference is affecting something else that is then affecting Wi-Fi. You might want to try an HDMI cable that is listed as being shielded to see if it would work without your having to ground the plug to the top case of your Mac mini.

I am having the same issue but I found a different reason for the WiFi issues then the other persons replying to this post.

I debugged over a week until I suddenly disconnected my HDMI monitor from my Mac mini. After that, my WiFi was stable with out any issues like packet loss or high latency. I then plugged in my HDMI cable again and the issue appeared again.

I change the HDMI cable to one with "perfect" isolation, but it doesn't matter.

After monitoring that behavior with the HDMI port, I debugged a little more and came to the result that as soon as the HDMI cable is to close to the Mac mini, the WiFi issues appears. This means, if I plug in the HDMI cable and the cable itself is going straight away from the Mac mini, there are no issues.

I got a confirmation to this behavior on reddit. Mac mini M2 Pro - WiFi issues.

It seems that the WiFi issues are home made by Apple. There is a big design failure in the Mac mini M2 Pro.

Unfortunately, it seems that there is no statement from Apple to these issues.

Can I just confirm this - I had the issues with my new Mac Mini M2 Pro and had Apple engineers calling me to go through several checks to isolate the problem. In the end I hooked up my two monitors through two new Thunderbolt (USB-C) to HDMI cables from Amazon and stopped using the HDMI port altogether and the issue is resolved. Clearly, the HDMI port inteferes with the wi-fi and is useless.

No, never tried. I use my machine for work, so do not want to mess with it.

Once I realised that replacing my previous set-up of one HDMI cable to one screen and a second Thunderbolt to HDMI to the second screen with a pair of matched USB-C to HDMI cables (Silkland USB-C to HDMI Cable 4K from Amazon) resolved all my problems, I left it alone.

So I have a Mac Mini 2 Pro that now works perfectly but with a redundant HDMI port (and loss of one Thunderbolt port because of that) but it works great and I will leave it like that.

I cannot see Apple taking all those machine back and reworking the HDMI port, but I assume they have changed the manufacturing of new ones to avoid the problem? If so, try taking yours back for exchange.

Ken Shimabukuro,

Regarding the test data provided for the cables, I would like to add some information:

Cable-1: HDMI to DVI:

I couldn't find any information about this cable. It was previously used with a Mac mini (2018) when using a wired network, so there were no Wi-Fi issues at that time. However, when used with the Mac mini m2 Pro, Wi-Fi problems occurred.

Cable-2: HDMI to MDMI:

This is the UGreen 20276 cable (https://www.amazon.com/High-Speed-Cable-Style-20276/dp/B076G4MKQ1?language=en_US). I couldn't find any information in the cable's details regarding shielding or passing EMI testing. Therefore, this cable experienced packet loss issues during the ungrounded testing.

Cable-3: HDMI to HDMI:

According to the packaging information, this is a product from a Taiwanese manufacturer, and the product description mentions that it has passed EMI testing.

Link: https://www.pc-3c.com/product.aspx?productid=774 (the product description is in Chinese)

During testing, Cable-3 already achieved a result of no packet loss during the ungrounded testing.

The difference between Cable-2 and Cable-3 lies in whether the product description explicitly mentions passing EMI testing. Therefore, my speculation is that using cables that have passed EMI testing might help avoid this issue.

Cable-4 is a Type-C interface (j5create JCC153G), which is not affected by this issue.

Okay, it's not the cables that are RF noisy. It's the M2 Pro Mac mini's HDMI port itself. That's why AbuYang's touching of the HDMI cable's plug and Mac mini's case reduced Wi-Fi interference. What did Apple change internally in this new generation of Mac mini?

Apple Community AbuYang's video: https://youtu.be/LlPGNIeyJkY

Thanks for the followup, AbuYang. A fellow community member said people were contacted by Apple employees, so hopefully Apple fixes this noisy HDMI port hardware issue soon. I wonder if Apple will need to make a hardware recall and replacement.

user Julian Wright replied on Jun 23, 2023:

> I wonder if there is any way to alert Apple hardware technicians of this forum thread.

They are already aware. A few of us have had phone calls from Apple Support engineers from Austin, Texas, who have remote connected to our Macs, had issues demonstrated to them, and they've collected megabytes of diagnostic files.

Could the HDMI cable be emitting 2.4GHz Wi-Fi signal perpendicular to the cable? I wonder. I see in AbuYang's video that his HDMI cable is coming straight out from his Mac mini, but can't tell if its looped back around towards the Mac mini. AbuYang, where is your HDMI cable routed?

I meant to write "...Mac mini then plugging the other end into your display without making the cable PARALLEL to the back of your Mac mini close to your Mac mini?, not PERPENDICULAR close to your Mac mini, sorry.

Hey Ken Shimabukuro

I don't want to jinx it, but since having the logic board replaced 6 days ago, there haven't been any wifi issues.

I've had wifi diagnostics running since then and no network loss.

I checked both before and after system reports, but couldn't see any difference in hardware/software versions etc.

I'll update here if I see any further issues.

Hi there,

I will have a technical call with Apple today. The result should be in replacing the logic board an/or the WiFi antennas. I think this will solve the issue. Keep you updated.

PS: How do I mark someone in the forum, so that his/her name is blue highlighted?

hi Eimer92

I think you'll find both the logic board and antenna will be replaced. I took mine in on a Saturday, it was ready the next day. Hope all goes well in your repair.

Copy and paste the user ID to get the blue link