Question No signal after boot/windows screen w/ DisplayPort?

Biggles_

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Hello,

I recently built a PC for a friend for his office. Main requirement was two displays and as a GPU wasn't needed I opted for a motherboard w/ two display outputs being HDMI and DP, I was recommend the B450M Mortar as it has the aforementioned ports though I needed to use an adapter for male DP to female HDMI. (Why do most monitors not have DVI these days?!) I was told motherboards with DVI would not be able to adapt to HDMI so I had to get this specific HDMI & DP capable motherboard which I'm not sure about but whatever.

The PC boots and runs perfectly with the HDMI connected. The secondary DP>HDMI monitor does not appear in windows at all and displays no signal on the monitor. With just the DP monitor connected, it displays the mobo splashscreen and the windows loading screen before going blank and never coming back, connecting the HDMI monitor turns that one on but the DP monitor remains blank.

DP monitor will boot to desktop in safe mode, connecting the HDMI monitor simultaneously makes the DP monitor lose signal and the HDMI monitor runs.

I've tried:
Switching on/off/discon. power multiple times for varying durations
Switching HDMI cables
Latest chipset drivers
Latest AMD drivers
Latest motherboard bios
Clear CMOS
Fresh windows format installed using DP setup connected only, installed fine but lost connection booting into desktop as previous

Mobo: B450M Mortar Titanium
CPU: Ryzen 3 3200G
Monitors: Acer 23.8" FHD IPS Monitor KA242Y

TLDR:
Trying to use two onboard motherboard display outputs for two monitors like this:
HDMI > Monitor
DP > male DP/female HDMI adapter > HDMI cable > Monitor

DP>HDMI adapter output has no display after mobo/windows boot screens
DP>HDMI adapter output works in safe mode (so I'm thinking it must be drivers not hardware related?)
In safe mode w/ DP output working, plugging other monitor w/ HDMI causes DP output to lose signal
Have never been able to have both outputs working simultaneously in safe mode or normal

I'm going crazy trying to fix this and feel terrible the PC my friend paid for isn't working as it should, any help would be massively appreciated,

Cheers,
Jacob
 
Last edited:

The_Prophecy

Splendid
Moderator
Not seeing any settings in the BIOS to force multiple active outputs from the integrated video ports, so it looks to me like a configuration issue with the AMD graphics drivers. See if there is a way to enable it in there. Will probably want to do it booting normally rather than from Safe Mode.
 

Biggles_

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Not seeing any settings in the BIOS to force multiple active outputs from the integrated video ports, so it looks to me like a configuration issue with the AMD graphics drivers. See if there is a way to enable it in there. Will probably want to do it booting normally rather than from Safe Mode.
Thanks for your reply. I've had a look in the AMD software but can't see anything about multi monitor setup in there and windows doesn't even seem to detect a second monitor in display settings or device manager. I'm confused because even if there is an issue with multi monitor, the DP output isn't working past boot screen even when its the only monitor connected.
 

Biggles_

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EDIT: Now I'm starting to suspect the adapter, I've read some similar posts and some indicate an ACTIVE adaptor is required if the output is single, not dual mode DisplayPort (which I suspect mine is). Annoyingly these posts don't have a resolution posted but I think I'll give an active adapter a go.

If the above is true I'm not sure how the adapter works in safe mode and boot screens but I'll give a new adapter a red hot crack and report back for the poor souls in the future trying to work this out.
 

Biggles_

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SOLVED! For any poor soul in the future reading this: I was unknowingly using a "passive" DP to HDMI adapter and not an "active" one. I won't pretend to know the intricate details but this fixed it instantly for me, hope it works for you!
 

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