# ATI Radeon 4650 blank screen using DVI-port

## jupi

Hi,

I just bought an ATI Radeon 4650 and drive it using the radeon driver (which works quite well even with 3D-acceleration). The card is connected to two TFTs, one by using VGA, one by using DVI. The monitor using DVI is right of the one using VGA. This setup has been configured in xorg.conf (via xrandr). The problem that occurs is the following: During boot-up, both monitors are active, image is cloned. When KDM starts up, only the VGA monitor remains active, while the DVI-connected one blanks out (but without going to standby - only image gets black). If I now turn off the DVI-connected monitor and turn it on again, it shows the image it should show - the background image of the login manager (or the right part of the desktop, if once logged in). So the configuration seems to be working and correct, the only problem is that on starting up X the DVI monitor goes blank and image can only be restored by powercycling it. Same problem occurs when switching the user: on the "new" X-screen (vt- :Cool: , the DVI-monitor blanks out until being powercycled. Turning VESA framebuffer on or off makes no difference.

With the nvidia card I used before the radeon, the TwinView setup worked like a charm, with the same setup of one VGA and one DVI-TFT, so there shouldn't be a problem with the TFT (and, btw, in Windows 7 it works even using the ATI radeon card without powercycling the TFT), so I think there is a problem with the radeon driver. Could KMS be a problem here? I did not knowingly enable it, and I read that it is so far disabled by default because of problems with DRI2.

Any ideas how to debug and fix this problem?

Thanks,

jupi

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## Herring42

I get a similar problem. If the monitor goes into sleep mode, I have to turn it off, then on again to wake it up.

This is with the GIT drivers and KMS (KMS has improved things a bit).

Bug in X somewhere...

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