Aha, so the first one shows “OL” = Open Loop or in some cases could be the reason for a ground loop also?
If it shows “OL” it means that this cable is not screened (copper braided) on the outside of the signal cables, since the metal shells of the connectors do not communicate and that is where the earth connection goes to avoid interference (EMI’s) along the entire length of the cable. When there is a ground loop problem, it is because all the “ground” are not unified to the same one.
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I would even try to limit eliminate Windows Processes and services that are not needed bs just looking at 3rdparty.
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I’m actually receiving a new SSD today (1TB Samsung 980 Pro M.2 NVMe) to use as a system disk.
Plan is to wipe my old 2TB Intel 660p M.2 NVMe SSD and use that as a data drive (Steam Library will be here).
Though I could migrate (with Macrium Reflect), I think I’ll just start over with the Windows install and only migrate the Steam Library using Steam Library Manager so I don’t have to redownload and re-configure all the custom games/mods stuff… 
I have full backup of the system, a USERS backup separately (taken Yesterday) and the full Steam Library.
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I tried thst before and it didnt help as far as i remember
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Remember my scenario is a bit different than Yours as my panels are completely off in 90Hz mode, but I’m not counting on it making any difference.
I just don’t do complete reinstalls very often (it’s been years) so I thought this was as “good” an occasion as any… 
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Yes of course good to try
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We have another user just posted on reddit with the same exact issue - i just linked him here:
@Robertsmania @DrWilken @Heliosurge @f1DaveK
I wonder if this really has to do with the drivers conflicting somewhere?!
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Some more testing today. 1.5+ hours without even a flash. I changed a few things
- Tried 75hz
- Unlooped the cable 1 time through the ferrite - so only 3 loops through the ferrites that i have
- Move the cable a bit further away from the PC’s POWER CABLE…
More and more and more testing to come lol - tomorrow the new optical cable is arriving.
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Today I ran another 2+ hours without a hitch and had some more changes:
- Updated to the latest Win10 update
- wore a grounding bracelet
No flashes or blackouts again.
I also received the “ground loop shielded” optical cable. After some careful inspection between my old one and the one I was sent - they look identical like nothing was changed at all. The thickness of the cable is identical. Both have a closed loop reading on my multimeter (not sure what they were testing themselves but my original one doesn’t show O.L. and beeps with a reading on all 3 points)…
So I’ll test their cable, but I may have already found the causes… I’ll have to backtrack to see which one of the recent changes fixed the blackouts from happening… I suspect that the cable was too close to the PC’s Power cable and that caused interference though.
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Was that something you added? The ferrites? To the Pimax cabling or something?
I am having this issue as well.
8kx
i9-10900k at 5.2 all core, 4.8 bus
EVGA 3090 FTW3 Ultra, Hybrid Air/Watercooling converted and modded.
- 500 watt bios. 2.2Ghz Clock, 10Ghz Vram
32GB G.Skill CL15 4000Mhz Ram
Samsung 970 Evo 1TB NVMe - Rebar Enabled
Asus MaximusXIII z590 Mobo
Fanatec DD1, CSL v3 Pedals, 7-spd/Seq and Handbrake
Yes i got 4 ferrites and looped thru only 2-3 times. Any more and i had issues but others said they use 4-6 loops through.
FT240-31 Ferrite Toroid Core is the type someone above recommended. I got mine from JPM Supply but you can find it elsewhere.
Has anyone here been using Bluetooth headphones by the way. That could be an issue itself by the way… just throwing that idea out there.
Cell Phones, BT Headphones, or anything with a wifi, power, bluetooth signals can interfere so just look around carefully at where your cable runs.
Ok so I received this new optical cable that they said is “ground loop shielded” - I didnt have much time in the morning to look at the differences but i noticed the diameter is exactly the same so i thought there must be no difference. I even quickly turned on the buzzer on the Multimeter that shows if there’s an open loop or a closed one (im not good at understanding this stuff), and thought it was the same until i just sat down and tested it again after what pimax told me.
Pimax reps said this after i asked them what the actual difference is in the new optical cable theyre having me test, and the old optical cables that has been out for a while. They said:
Update from hardware engineer, “The previous optical fiber line is also grounded, but the shielding layer is directly grounded with the board end, it is not grounded to the outer iron shell, now it is directly grounded with the outer iron shell, so the shielding area is wider, you could have a multimeter to measure it. It’s an internal adjustment, it must be the same outside.”
So i took the multimeter and back to the old cable and new cable and found some DEFINITIVE changes in the cable…
Old Cable:
When i touch both the USB and DP, it buzzes and shows a value of under 1.0 generally.
When I touch the Connector side that goes into the HMD, and the other side on USB or DP, the Multimeter DOES NOT go off and just says “OL” - Open Loop…
New Cable:
When I touch USB and DP, it buzzes and shows a value bouncing between 1.0-2.0
When I touch the Connector side and DP, it buzzes and shows 2.0 - 3.0
When I touch the connector to USB it shows around 1.0
So it seems that between the Connector and the other ends, it has an Open Loop on the optical cables, that MAY contribute to some of our issues.
I’ll be testing the new cable starting tomorrow and will report back
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What rank is Jimmy? 20 chars
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Just got the latest beta fw to test. 3rd day of absolutely no flashes or blackouts.
Today i removed the grounding strap i wore yesterday - so that’s definitely not the issue
Im going to go a few steps backwards to try and induce a blackout to figure out the cause. My suspicion is that the pimax cable was touching either the PC’s power cable, or other cables that are on the back of my PC - including my buttkicker’s sound cables that someone mentioned they also had near their pimax cable and were also having blackouts.
When i have some time, I plan to put the cable next to those other cables and see if the flashes or blackouts return.
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Anyone here using buttkickers?
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I have a buttkicker gamer 2 and then 2 clark synthesis 289s. I am also on PT actuators and while I do get blackouts, it only happens when I touch the sides of the HMD covering the sensors, if I grab the middle to adjust I get no blackouts. I definitely do not get blackouts randomly without touching the hmd though like you are. I do use some ferrite but no loops through as I don’t have enough cord.
I have a PT rig also - but touching the sides only blacks out the headset when i didnt have a large ferrite on the cable - thats a different type of blackout where it’s loss of tracking.