Black screen for 2 seconds - Every so often

[Rocky-Roader]

Hi Again.

Since building the PC a few months ago, to my knowledge this problem has only started in the past week.

The issue is that every so often - I get a blank black screen for about 2 seconds - and then everything is normal.


I first noticed it when I lent over the monitor to plug my printer into the USB port, however because I was behind the monitor and not expecting it to go off - I don't know if it went off when I plugged the printer in to the USB port - or because I lent over it - or if it was a coincidence and windows just happened to cause it.

I gave the monitor a little wobble, checked the cables - to rule out a loose connection inside etc - but still I still couldn't replicate the problem.
I then unplugged the printer and plugging it back in a few times - still couldn't replicate it.

I came to the conclusion that perhaps Windows was doing an update in the background or something.


2 days later - I was on eBay and moving photos from my phone to my PC and out of the blue - blank screen for 2 seconds and then back to normal.

This time I was thinking perhaps it is something to do with the USB - but my printer goes in the port at the back of the motherboard and my phone was in the one at the front - so it can't be a specific USB port causing it... tried unplugging the phone and plugging it in several times but still couldn't replicate it.


Everything seemed fine again until late last night, I was watching NCIS on the Channel 5 website with headphones in, when the episode finished I unplugged the headphones from the audio jack - black screen for 2 seconds again... tried plugging them back in again and unplugging them again but still can't replicate it.



What has changed to the PC in the past 2 weeks...

1) I started using a new monitor - my MSI b850 Gaming Plus Wi-Fi motherboard does not have a HDMI port so it was originally connected by a DP to HDMI adaptor and a HDMI cable. (the problem didn't happen with that cable setup - but I only used it a couple of times so that may just be a coincidence)
2) I've updated the bios.
3) I purchased a DP cable with gold connections to eliminate the need for a DP to HDMI adaptor.
4) I've replaced all 6 case fans which were originally on full power all the time as they were powered by the PSU - and replaced them with fans that connect to the motherboard so don't run as fast.

I'm assuming the possible causes are...

1) - Problem with the new DP cable.
2) - Problem with the DP port on the monitor.
3) - Bios problem.
4) - Some sort of driver problem caused by changing the monitor cable - but with my motherboard not having a HDMI port the DP port is used regardless of the cable.
5) - A motherboard or CPU issue that has only started developing recently and may get worse.

I'm still using the stock cooler and my Ryzen 7600 CPU has graphics built in so I don't have a separate GPU.


Not being able to replicate it makes it harder to try and nail down the specific cause.


Could it just be a coincidence that it happened when I unplugged the headphones?

Thought I would ask if anyone else has encountered a similar problem?

 

[Rocky-Roader]

Strange innit

I've just stuck on another NCIS episode and realised that when I unplug the headphones - the video freezes (just like if you'd unplugged the wi-fi) then starts playing again when I plug them back in - so the Channel 5 player must somehow know I'm disconnecting the headphones.

Just tried BBC iPlayer and that does not freeze when I unplug the headphones.


I've just gone onto the MSi website and downloaded the driver for the monitor - however it's a November 2024 driver so is fairly old - so I'm not sure if that'll do much.

 

[Rocky-Roader]

Have you looked at the event viewer entries for the time of the black screens?

Good thinking!
Around that time I see some 'windows update process' logs - so it does look like it could be update related... Next time it happens I'll check the logs first,

There does seem to be a few critical and errors in the log from other times it looks like most of them are to do with fast start or shutting down - does everyone get these?

If you drop refresh rate to 60Hz, does it do it?

There hasn't been another black screen yet since installing the driver but if it does I'll also give this a try

 

[Rocky-Roader]

I do when I forget to get rid of that option (fast start in Windows)

The fast start option on my PC is checked - but greyed out - I can't uncheck it

Edit ^^^ just realised it says "change settings that are currently unavailable" - I've now unchecked it, but I don't know why it was unavailable.


Well... it seems like there may be 2 problems.

It's only happened two or three times when I've been actually sat down using the PC - as in not touching anything near the tower - just using the keyboard and mouse. (that problem may just be updates)


Every other time it seems to be when I'm either leaning over to plug something in to the USB... and there appears to be the main problem.

I've been using my keyboard on my old PC too so I can sort what I want to transfer over and what I want to scrap... I've just come in and booted up the new PC... went to connect the keyboard and hey ho blank screen.

Investigated by unplugging and plugging back in - no black screen for unplugging - if I plug it in quickly no blank screen either.

But if I carefully plug it in as in making sure I'm not forcing it and its going in straight - as the USB connector touches the USB port - the screen goes blank.

It appears that if the metal frame of the keyboard USB connector touches the metal on the outside of the USB port - the screen goes blank.

Further... the screen goes blank every time if I...

• Touch the metal on the outside of any of the USB ports with the keyboard connector.
• Touch any of the case fan screws or rivets on the back of the PC with the keyboard connector.
• Touch any of the PSU screws with the keyboard connector.
• Touch the gold metal on-board Wi-Fi connectors with the keyboard connector.
• Touch the 4 thumb screws that secure the glass side panel with the keyboard connector.

Just done the same tests with my mouse - the exact same thing happens.

Keyboard = Microsoft 600 Wired.
Mouse = Microsoft basics.

Just tried a HP mouse - screen went blank once - can't replicate it again.

Back to the Microsoft mouse - blank screen, a couple of times it felt like the screen went blank before I'd actually touched the port.

The screen on my old PC never goes blank when I plug the MS keyboard or Mouse in or touch any of the screws with it.

I think... I may have an earth problem?

 

[Rocky-Roader]

What resolution and refresh rate is your new monitor? Is display stream compression enabled?

My monitor is an MSi MP272L - it says the refresh rate is 100 Hz and the resolution is 1920 x 1080.

But in Windows, the refresh rate seems to be set at 59.94 Hz - by default

 

[Rocky-Roader]

Does sound like it. This is not something I know much about how to troubleshoot.

Turns out that either the DP port on my new monitor is iffy or the cheap DP cable causes the issue.

The DP cable I have is this one and only £6 I'm going to look for a £10+ one to try to see if it still happens.


If touching a screw on your case with a USB cable or plugging a USB cable in makes your screen go blank for a second - would you guys say that is an issue? or am I just being fussy?

 

[Rocky-Roader]

If you did what is the case and did it have some mounting screws in place already? (slim chance one may have been misaligned)

It's a Jedel Trooper SX81, around £40 so its only a cheapy, it didn't have any mounting screws already fitted,

I do remember reading some reviews for other cheap cases at the time on Amazon and I'm sure I read one which mentioned 'grounding' and how someone had made an adjustment to theirs but I don't know if it was the same one - so trying the mobo outside the case may be a good shout.

Although my motherboard only has a DP port, no HDMI and this only happens when using a proper DP cable - not if I use a DP to HDMI adaptor or a DP to DVi cable.

Should I strip it down and try it outside the case first? or buy a better quality cable to try?

 

[Rocky-Roader]

If you're connecting the plug through an adapter it might not be grounding the monitor properly and that's leaking through the DP cable?

I don't have any euro plugs, I'm using a 4 way extension but I have also tried plugging the monitor and tower directly into the mains sockets and still get the same problem.

Sorry for any confusion... my motherboard only has a DP port - no HDMI port

I originally used a cheap DP to DVi cable with my old monitor - this problem doesn't happen with that.

Then I got a new monitor but it came with a HDMI cable so I used a cheap DP to HDMI adaptor - this problem doesn't happen with that.


The problem only seems to happen when a proper DP cable - I don't have a better one to try it with yet


If it was a problem with the tower, would I not still get black screens when using the DP to HDMi adaptor? (as its still using the DP port on the motherboard - this is why I was leaning towards the cheap cable being the problem)


BTW, thank you to you and everyone else for the helpful suggestions in trying to solve this

 

[Rocky-Roader]

I was looking at this Prevo DP14-2M on eBay for £7 but others seem to be selling it for £10+

OCUK don't appear to have any dearer ones at the minute

 

[Rocky-Roader]

New cable arrived today.

Got a £8 one from AliExpress in the end which is the same as some of the £14 ones on eBay, looks and feels good quality but doesn't have the push release style connectors.

Anyway... fitted it - but the problem remains.

Unlikely that 2 cables can both be faulty so I'll start investigating further tonight - not the way I was expecting to spend transfer deadline day!

Plan:
1st - Try it with just a power cable and monitor connected.
2nd - Disconnect the fans (not the CPU cooler fan) and try it.
3rd - Inspect all the wires from the PSU. (unlikely as i'm super careful but will check anyway)
4th - Try my spare Corsair PSU. (again unlikely but never say never)
5th - Motherboard removal.

Just out of curiosity...
If I remove the motherboard from the case and the issue still happens when I touch the metal on the motherboard backplate - where would I go from there? motherboard? monitor?

2 things I've bought this weekend that should have been easy jobs have turned overly complicated so I'm expecting this to go the same way

 

[Rocky-Roader]

I'm still not entirely convinced the problem doesn't lie in grounding somewhere between the monitor and the cable, since the problem doesn't exist with an adapter which suggests it is sorting it somehow (maybe because of how it terminates). I'm not an electrician, so eh, what do I know.

You may not be an electrician but your assumption appears to be... spot on!

Tonight when moving the PC into the kitchen to put on the table ready for investigating... I accidentally dropped the 4 way socket, thought nothing of it but when I switched it on to test it out after disconnecting the fans - I couldn't replicate the problem (with the first OCUK DP cable) despite messing around with it for 20 minutes.

Connected the fans back up - still no problem.

Tried the new DP cable from AliExpress - no problem either.

Connected the first OCUK DP cable again - problem back.

Switched the cable round so the plug that was in the PC is now in the monitor - no problem again. (the reason I thought to try this was because I noticed the cable didn't lock into the motherboard and I'm fairly certain it was locked in when I first tried it)

So it looks like the OCUK DP cable is faulty at one end.


Then I moved the PC back into the living room and... the problem returned!

But this time I was on the ball, the 4 way connector - no problem after I dropped it when moving it... I whipped the back off (obviously I switched it off and unplugged it first) and found that the screw for the earth wire was barely tightened.

Tightened the earth screw and as of the last hour - no more blank screens.



So it looks like the problem was a combination of a faulty cable at one end and my 4 way socket... when I plugged it directly into the mains to test it last week, I didn't think to plug the end from the monitor into the PC instead to see what happens.


Fault finding by dropping a 4 way adaptor sounds like something you'd see on a Lee Evans stand up DVD - so I'm going to keep playing around with the PC for a few days just to be sure the problem is definitely gone - fingers crossed

 

[Rocky-Roader]

The other day out of the blue I got a black screen again after unplugging my headphones and although I couldn't make it happen again it has been bugging me.

Tonight I decided that I would plug the old DP cable back in which constantly caused the black screen issue and then remove the motherboard from the case and also try it without the front panel usb/sound connected just to 100% rule out an earth issue.

However, since putting the old DP cable back in - I cannot replicate the black screen issue when touching my USB keyboard connector against any case screws, rivets or USB ports.

I haven't changed any cables or taken the PC apart or moved it since the other week when the issue was easy to replicate so can't see how the issue can be gone

 

[Rocky-Roader]

Sorry for the late reply,
I wasn't wearing a jumper but I do often polish the surface of my desk so the duster could cause static, especially as sometimes I would have touched a usb cable a few mins after polishing the desk.

Currently the problem is happening when I plug my printer cable into the motherboard - or when I touch the printer cable against the DP socket on the monitor. (only happens with the printer cable now - no other USB device)

The monitor has an adaptor rather than an actual plug - I wonder if that is earthed?

My printer USB cable is fairly old - I'm going to try another,

I probably sound like a complete nutter but it gives me a constant niggle that I can't trust it and one day the screen will go blank and not come back on - almost like id expect from a cheap second hand system not a brand new one lol

 

[Rocky-Roader]

when I touch the printer cable against the DP socket on the monitor.

Why would you do that lol.

I thought that if I did that and the monitor didn't go off - it would mean the problem would deffo be at the PC end lol


Stripped the PC down... motherboard on cardboard - problem remains.

Tried different USB and power cables on the printer, still happens.


Tonight I even found that if I touch my mouse USB connector against the old metal TV bracket on my wall which is a foot behind the monitor - the monitor goes blank for a second lol... only happens when using the DP connection with the monitor - fine with the HDMI cable connection