HDMI to VGA Adapter works for some seconds and then black screen.

alexakis99

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Dec 2, 2012
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Hi there,
i just received a HDMI to VGA adapter to use for my laptop(hackintosh to connect to my second port of my display to change it when i want to use it)It works fine for 10-30 seconds then the display starts making lines and then it goes completely black and sometimes it "blinks".The weird issue is that with one vga cable i am able to display up to 720p(something close) and on the other cable i can display 1080p just fine.Both have the same problem.When i disconnect and connect again the adapter it matters how long i leave it unplugged to how long it shows output.Meaning if i plug it in, wait for the monitor to go black and remove it and plug it again immediately then it will either still black or show output for 1 second.But if i leave it for let's say 10 or more seconds it can show upto 30 seconds before going black.
I have uploaded a video for you https://www.youtube.com/watch?v=omJMen9dMxk
 
I think your video left one thing unclear, is the adapter passive or active (with it's own power supply) Since I think it is quite common to experience problems with passive adapters.
Main reason is that VGA is analog, HDMI is digital and some chip must do the conversion and that needs power.
 

No,it doesn't have an external power supply,only HDMI.You can see how it looks here http://www.ebay.com/itm/331640682484?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

 
well, said adapter is in the dubbed "gray" area. It either works or doesn't. It all kind of depends if the HDMI can give it enough juice to run the conversion or not.

This might or might not be fixable by altering power saving settings on the laptop but general idea is that the only way to get it to always work for sure is to use active adapter with external power supply (either it's own plug or with power supply though separate USB port connector)
 


Just tried with my desktop and had the same problem.So it seems that it doesn't matter in what computer is plugged in.I would guess that i can't modify it to use external voltage(from usb let's say)since it probably has a built in voltage amplifier and would maybe blow the whole thing up