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| | | Supreme Being
Group: Forum Members
Last Login: 9/10/2009 3:10:30 PM
Posts: 82, Visits: 184 |
| | This is not because overheating. Setting darked backlight won't help. The only reason this happens is because you use resolution bigger than 640x480. Chip that downscales it probably badly cooled down, so around hour playing 800x600 you will see dot growing right side. Playing 640x480 you'll never see it again. |
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| | | Forum Guru
Group: Forum Members
Last Login: 8/3/2008 8:12:30
Posts: 55, Visits: 116 |
| Hi,
I actually did some tests with the VR920 disassembled to figure out where the heat came from and it turned out that the backlight contributes very little, if any to the heat produced but in fact, as you stated from a chip mounted in between 2 PCB's, located between the lenses ... I had problems with the LCD picture quality worsen during gamplay and sometimes the black dot growing on the right side of both LCD's ... My solution was (Dont do this yourself unless you're willing to void your warrenty) to cut a approx. 3x1,5cm hole in the top and bottom of the casing, adding a grille on each side.... I got 2 benefits from this, I didnt get all sweaty around my eyes (I use the immersive shield) as they dont get as hot and the artifacting and black dot problem hasnt appeared since. It wasnt really a difficult operation, 4 screws removed, the casing removed and modified using a dremel and some plastic grille (coarse so the air can escape as theres no fan in there  ) added bought from a hobby shop for the model hobby, works fine and looks great.
The reason for me doing a vent in both the top and bottom of the casing is to prevent finding a dc source for a fan in there, when the hot air rises (lighter than cool air), the volume that escapes above will need to be replaced, otherwise a vacuum (small but existant) would occur and the hot air wouldn't escape, with the vent below, the volume of hot air escaping above, can be replaced with cool air from below.. As an added bonus the cool ar are denser than hot air which means that the heating of the cool air will create a pressure withing the glasses causing some turbulence and add cooling and force to expell the hot air ... These forces are weak and low though but seems to work fine and I haven't noticed any need for active cooling. |
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Supreme Being
Group: Forum Members
Last Login: 12/25/2011 3:17:03 PM
Posts: 322, Visits: 514 |
| Its cool you found a fix, but I'd just like to state I've been using the VR920 for over a year and have never seen this black dot you guys are talking about. I mostly play on 800x600 all the time, but sometimes at 1024x768 and have never seen anything like this. Even when playing for extended sessions (over 1 hour). This may be some sort of defect, if it were a common problem I think more people would have mentioned it before.
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| | | Forum Guru
Group: Forum Members
Last Login: 8/3/2008 8:12:30
Posts: 55, Visits: 116 |
| I think you're right in that it's not a comon problem as this post is the first I've heard being similar to mine, the black dot and pixels being stuck over a period of time, I think mine gets hotter than average due to the problems I've experienced but it's all gone with the vents ... I know I could have returned the set for a warrenty repair but my fix seems to work fine and being in denmark, returning the set would be kind of a hassle 
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Supreme Being
Group: Forum Members
Last Login: 2/5/2012 3:32:51 PM
Posts: 386, Visits: 3,704 |
| | I also saw the described problem with the black-dot, but it was only one time, I turn off my VR920 - give it rest a bit and then all is ok till now (for a week I think). |
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| | | Supreme Being
Group: Forum Members
Last Login: 9/10/2009 3:10:30 PM
Posts: 82, Visits: 184 |
| | I think black dot could appear on 640x480 too, after around 4 hours playing, but rare i play that much. on bigger resolutions it happens just after 1 hour of playing. And kinda darker games - less hot, more time. |
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Supreme Being
Group: Forum Members
Last Login: 12/25/2011 3:17:03 PM
Posts: 322, Visits: 514 |
| Wait, are you leaving the VR920 plugged in via USB 24/7? That can cause issues, at least with the old firmware.
I always make sure to unplug the USB cable when I'm not using it. That should help with heat and burn-in related issues so maybe it will help with this black dot thing.
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| | | Forum Guru
Group: Forum Members
Last Login: 8/3/2008 8:12:30
Posts: 55, Visits: 116 |
| | Mines never been connected for more than a couple of hours at a time and I've experienced the black dot on more than one occasion, even worse, large areas of pixels looked weird for days after the dot appeared the last time, funny thing is that this pixel error gradually dissapeared afer a couple of days, looked like drops of water or something ... My modification eliminated all these issue for me though. Usually always run 1024x768 as this is the minimum res. for FSX and this is what I use them for the most except an occasional movie or such. There was no pattern on when it would happen, sometimes it ran for hours without problems, others 30 min. |
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| | | Supreme Being
Group: Forum Members
Last Login: 9/10/2009 3:10:30 PM
Posts: 82, Visits: 184 |
| | Yepp, i always disconnect vr920, because i use same usb port for other devices ) It's not a big problem, 10 mins cooldown and you can play hour more. There is some kind of air flows that should happens normally around glasses. My next guess is changing position causing overheat. Two times i was expiriencing it, when i turned on edge when laying in bed. Still this is too hard to check that. If i could see temperature same what i do for cpu and gpu.. Also i think would be good to try just add some passive radiators to glasses, they will increase space of cooling, and won't break warrancy, as you don't need do holes. All this troubles have to be solved in future anyway, since there is limited number games i can play, i can't test alot. So i wait a good stereodriver, will that be nvidia one, or vr920 universal driver like iz3d do. |
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| | | Supreme Being
Group: Forum Members
Last Login: 9/10/2009 3:10:30 PM
Posts: 82, Visits: 184 |
| | Was turned on around 2 hours in drawer, so no good air conduction. When discovered dot was around 1/6 of width in radius. Just 3 minutes off and it dissapeared completely with no damage. |
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