[SOLVED] Dual monitors randomly lose signal - please help :(

May 19, 2021
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Hi all,

Before i start let me acknowlege that there are a tonne of posts already about this issue, and yes ive learnt and utilised a fair amount of the advice, but to no avail. As im writing this post, im just hoping my monitors dont black out with its random, no warning 'no signal detected'. Lastly, please bare with me i know its a lot to read but i do believe the full context is required in order for someone to really understand both the pain ive had to live with and also hopefully help with being able to diagnose the issue.

The issue started about 3 weeks ago, where randomly my dual monitors would simultaneously lose signal (PC would still run though in ALL instances not a hard shut down) forcing me to hard reset and hope the next time around it survives long enough to allow me the joy of joining my friends to play the games i love. However the nature of occurance of this issue happens way too frequently now and im hoping someone here can pin point what the likely culprit is.

In terms of troubleshooting steps so far:
1. I have a Corsair HX1000i PSU, i noticed on HWinfo that the 12v rail would fluctuate at times reading 10.9 and even a 10.0 reading, AH HA! i found the issue, i checked BIOS voltage readings same fluctuations i.e. essentially lower than the 5% threshold. After reading many forums on this, i wasnt rash to jump to conclusions and the only way id know for sure it to run a multimeter reader. My brother in law is an electrician, so i borrowed one, grabbed a 4pin corsair plug with a molex at the other end, tested it a lo and behold it reads 12.12v...surely this cant be right? tried again and yep its 12.12 - unless ive tested this incorrectly, and yes this was underload with all other peripherals connected etc.
Conclusion 1: Not the PSU (also given its a 1000i it was never going to be a load issue, or at least im assuming it wouldnt be).
2. Next issue, my GPU, its a GTX980 which ive had for over 5 years now and its treated me well, surely monitor signal and GPU have something in common. Immediately i suspected that this had to be it, maybe this card which has served well for many years has decided to call it quits, now silly me i probably should have ran to the store, grabbed a DVI cable and used the integrated graphics to test this to be sure right? well unfortunately i wasnt as patient with this like i was in step 1, so i went out and purchased a GTX 1070ti, in a way i thought look i got it for a good price, its an upgrade and worst case ill just sell the GTX 980. So after plugging it in, performing a DDU to uninstall and downloading the latest drivers (no shutdowns in monitors as well at the point which is great), everything seemed to be great. Heck i even played a little Warzone just to see what would happen and nothing, working a treat! 4 hours later i launch a game, the action of opening the game immediately causes the monitors to go out again, at this point i wish you there to see my facial expression, one side of me was happy that at least my GTX980 was still alive, the other was, why on earth didnt i just buy that DVI as it would have proven the graphics card wasnt the culprit.
Conclusion 2: Not the GPU
3. Well back to the drawining board, i had a bit of dust build up so i cleaned EVERYTHING, reseated memory (dual channel 16gb), reapplied cpu fan, new thermal paste, analysed temps, looked at all the pin connects, PSU connections, and still no luck.
Conclusion 3: Not due to dust or any visible cable issues
4. I removed all the plugs from my monitor (using display ports) plugged them in again, but again i never assumed it would be a monitor issue given both of these would go out at the same time, very unlikely that both monitors failing or that both cables are broken, so im certain its not a monitor issue.
Conclusion 4: Not the monitors or cables associated with the monitors.
What does this leave me with?
Memory
Motherboard
CPU
5. As im writing this, ive taken one of the memory sticks from the motherboard and running 8GB instead, so far so good as its allowed me to write this post without shutting down the monitors on me. If it fails ill switch around the sticks as ive also read that it could be faulty RAM, i did reseat the sticks before this though but that didnt help, and yes, they are firmly placed into the slots, i literally couldnt push down any harder. So whilst i cant conclude just yet that it is fault RAM, ill update the post to after a day or so (As this is generally the maximum threshold before the monitors lose signal again, at times im not so lucky and it will happen the moment i log on to windows).

Other things to note:
*Im not sure if its a coincidence or something is happening here but after reseating RAM or the video card i tend to have a longer amount of time before the next wave of monitor shutdowns occur, several hours rather than minutes again not overly sure if this is a pattern but i thought id mention it.
*I noticed that one half of the motherboard pins that plug into the PSU wasnt firmly placed and would easily pop out (no holding clip on the cable like the other cables), but this time i firmly pushed it in, i mean i assume it cant be that simple can it? given that the PC wouid still be on, i can literally talk to friends on teamspeak with shutdown monitors lol.
*Temps are fine from a CPU/GPU perspective - so not an overheating issue.
*One last note, i had an issue about 2 months back where i was experience hard restarts on the PC and the blue screen of death. Fortunately i had a backup windows on another drive and was forced to switch over (no restore point) and i never worked out why that happened, i have heard that it could be linked to motherboard issues, but not overly sure. If i try to switch back to that drive im almost certain the BSoD will appear again, so ive stayed clear from booting from that drive. Im probably due for a fresh format at some point i guess, but havent really been bothered.

Hoping someone can help and verify whether the assumptions and conclusions ive made above are solid or is there something obvious or incorrect ive done as part of the steps conducted thus far.

Thank you for reading.

Specs
CPU: i5-4690K
Mobo: GIGABYTE z97X Gaming 7
RAM: 16GB Kingston DDR3 1866
PSU: HX1000i
 
Last edited:
May 19, 2021
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Hi all,

Just an update, it seems that the volatage variations have stopped fluctuating on HWinfo. I thought what on earth why is it showing a stable 12v now, it seems that on the 24 pin connected which is split (PSU input end), the 10pin slot wasnt firmly pluged into the PSU, it has a tendancy to push out slightly, i poushed this in as hard as i could and noticing a constant 12v. Maybe the issue was caused by drops in voltage that was happening intermittently?

PC has remained to be on for over 12hours now with no sign of monitor signal failure, ill update this thread in another week to be sure.