Question Monitor displays no input signal on boot up with DP until an HDMI is connected.

[Amet DeCrypt]

I've been having an issue for as far back as I've had this computer. I've gone through 3 CPUs (Intel and AMD), 4 GPUs (2 Nvidia, 2 AMD), 3 motherboards, 2 monitors (A 60hz dell and a 144hz HP with freesync), and windows 7, 8 and finally 10. Every single one has presented some version of this issue where on boot, my monitor just doesn't show any input signal. Sometimes it required another reboot, sometimes it required draining power for 1 to 45 minutes, and sometimes it just required jiggling and moving the cables to different ports and back. The only constant has been that I've been using a DP cable to connect the GPU to the monitor, and even that I've changed out quite a few times.

The latest permutation of this just popped up when I updated windows and rebooted, and it wouldn't show any video. I fiddled around a bit and plugged an HDMI cable in to the monitor and GPU. Suddenly the video is restored, and I can swap back to displayport like nothing ever happened. The thing is, My monitor only has 2 inputs, and I'm using the HDMI for my xbox, and I despise having to go under the desk and fiddle around with cables with every single reboot. I tried disabling fast startup, but that didn't help either. My motherboard only displays 9E which google says just means TPM is active.

The problem right now appears on the surface as if the GPU doesn't want to wake up when it receives a DP signal, and will only do so on HDMI. I'm at my wits end after dealing with this for nigh on 12 years. This issue occurs off and on. Twice it got so bad that I even broke down and paid for geek squad's premium subscription for them to deal with the issue, and ended up having to undo the internal cabling party they'd engineered when I got it back with nothing but a "I dunno man, it worked when we tried it."

I just wish I could just get a solution once and for all, but it seems that nobody else on the face of the internet is experiencing the same problem as me.

Current hardware:
CPU: 5900x
GPU: Saphire Nitro+ 6900xt
Monitor: HP 25x 1080p w/ freesync and DP 1.2 settings enabled
Motherboard: Asus ROG X5790-E Gaming
RAM: Gskill Trident Z neo 3600 32gb
Boot drive: Samsung 970 Evo 2280
PSU: Rosewill photon 850w 80 plus gold

 

[boju]

Would think after so many changes something would give.

Had a 2600k p8p67 system with 1080ti connected to xb270hu via DP. With this machine i had to turn on display (not left on standby) via button a second or two after turning on pc for it to display consistently from boot. Otherwise maybe 1 out of 10 times turning display on first wouldn't show. Dealt with that for several years. This order of turning things on didn't matter anymore upgrading to 11th gen intel with same gpu. It's a shame nothing changed for you.

Difference between your situation and Geek's is they wouldn't have tested your monitor with multiple devices? Have you always had this setup in those years sharing monitor with pc and console? Hdmi could be prioritised if something else is connected. Maybe switching input to DP in monitor before or after turning pc on might help.

 

[Amet DeCrypt]

Well I'm not booting up the monitor. I'm booting up the computer. It doesn't matter what else is connected to the monitor. I've had it with and without other devices connected to it. Switching input also hasn't ever helped, but right now it won't just fix after I've plugged into HDMI, I must also switch to HDMI input to show the desktop in order for video to be restored.

 

[boju]

Well I'm not booting up the monitor. I'm booting up the computer.

I don't understand why you said that.

 

[Amet DeCrypt]

I was just clarifying, in case you'd thought I meant turning on the monitor.

 

[boju]

So what order have you tried turning things on? Pc then monitor. Monitor then pc. Seconds apart.

I know you tried multiple DP cables, but what brands were they? Chances of four cables doing the same thing be pretty slim, although possible same design of cable was bought with 20th pin connected.

Avoid graphics card damage - The DisplayPort Pin 20 Issue Explained - Cable Chick Blog

Incorrectly made DisplayPort cables can cause boot issues on PCs. Find out why this was ever a problem and how correctly manufactured cables aren't affected.

www.cablechick.com.au

If you wish to try another DP cable for a known good brand to be sure, they are Accell and Club3D.

 

[Amet DeCrypt]

The DP cables I've tried were the generic insignia brand DP cable that came with the monitor, and a slightly more expensive 1.4 cable from "iVANKY" on amazon that's apparently vesa certified. I also had this issue with HDMI, but that was with my last motherboard that I had to RMA. I'm going to try a few boot orders, I'll post the results shortly.

 

[Amet DeCrypt]

Well I'll be dogged...


I first rebooted the computer with the monitor powered off for a baseline test. Upon waiting for the mobo code to settle and powering on the monitor, the screen showed up windows. I then rebooted with the monitor on and received the same issue as before. I power cycled the monitor and it then showed video when the monitor turned back on. To test, I rebooted with the HDMI cable unplugged and got the exact same issue as when plugged in, but was able to power cycle the monitor and get video back again. I'm doing one more test with DP set back to 1.1 on the monitor.

 

[Amet DeCrypt]

Reboot with DP 1.1, no change. I don't get what's going on, but I guess resetting the monitor is a sight more convenient than fiddling with cables, and a lot more cheaper than getting a whole brand new monitor to hopefully possibly fix the issue. I can live with this workaround, but I'd honestly rather find and fix the root cause at some point, because in the past, this issue has completely prevented the computer from even POSTing until I did whatever fix worked at the time, and the solution always seems to be changing as I update parts and software.

 

[boju]

Any of your friends have a monitor worth trying for a night? See what happens. Guess everything you changed, that's the only thing that remains right? Wonder if the monitor has firmware capable of updating? Possibly it's getting confused between different DP versions.

LG make nice monitors.

 

[Amet DeCrypt]

I've tried different monitors too. The type doesn't seem to matter.