Samsung 204b 20" LCD blinking on DVI 1600*1200 - Analog

[endeval]

Hi all
I hope someone can help me please.

I have a GeForce 68000 Ultra and bought a Samsung 20" LCD

Native res is 1600*1200 @60Hz +/+ polarity.  
Using Analog connection, no problems
Using DVI at 1600*1200 - monitor flickers on and off
Using DVI at 1280*1024 - no problems

I used pstrip customer res from EDID, and my own custom res, same issue...
Tried every single nVidia driver under the sun, same issue


Many thanks in advance.

James.

[endeval]

Here is the moninfo while connected as analog.

I keep thinking the EDID info the monitor is throwing the Card is corrupt or wrong?!?!?

Monitor
  Windows description......... SyncMaster 204T/204Ts/204B,SyncMaster Magic CX201Ts(Analog)
  Manufacturer description.... SyncMaster
  Manufacturer................ Samsung
  ?
  Plug and Play ID............ SAM01AD
  Serial number............... HSHL800048
  EDID data source............ I2C bus (real-time)
  ?
  Manufacture date............ 2006, ISO week 32
  EDID revision............... 1.3
  Display type and signal..... Analog 0.700,0.300 (1.0V p-p)
  Sync input support.......... Separate, Composite, Sync on green
  Screen size................. 410 x 310 mm (~22")
  Power management............ Active off/sleep

Color characteristics
  Display gamma............... 2.20
  Red chromaticity............ Rx 0.640 - Ry 0.330
  Green chromaticity.......... Gx 0.300 - Gy 0.600
  Blue chromaticity........... Bx 0.150 - By 0.060
  White point (default)....... Wx 0.313 - Wy 0.329

Timing characteristics
  VESA GTF support............ Not supported
  Horizontal scan range....... 30-81kHz
  Vertical scan range......... 56-75Hz
  Video bandwidth............. 170MHz
  Extension blocks............ n/a
  Timing recommendation #1.... 1600x1200 at 60Hz
      Modeline................ "1600x1200" 162.000 1600 1664 1856 2160 1200 1201 1204 1250 +hsync +vsync

Standard timings supported
   640 x  480 at  60Hz - IBM VGA
   640 x  480 at  67Hz - Mac II
   640 x  480 at  72Hz - VESA
   640 x  480 at  75Hz - VESA
   720 x  400 at  70Hz - IBM VGA
   800 x  600 at  56Hz - VESA
   800 x  600 at  60Hz - VESA
   800 x  600 at  72Hz - VESA
   800 x  600 at  75Hz - VESA
   832 x  624 at  75Hz - Mac II
  1024 x  768 at  60Hz - VESA
  1024 x  768 at  70Hz - VESA
  1024 x  768 at  75Hz - VESA
  1152 x  864 at  75Hz - VESA
  1152 x  870 at  75Hz - Mac II
  1280 x  960 at  60Hz - VESA
  1280 x 1024 at  60Hz - VESA
  1280 x 1024 at  75Hz - VESA
  1600 x 1200 at  60Hz - Samsung
  1600 x 1200 at  60Hz - VESA

Raw EDID base
  00: 00 FF FF FF FF FF FF 00  4C 2D AD 01 30 32 52 42
  10: 20 10 01 03 0E 29 1F 78  2A EE 95 A3 54 4C 99 26
  20: 0F 50 54 BF EF 80 A9 40  81 80 81 40 71 4F 01 01
  30: 01 01 01 01 01 01 48 3F  40 30 62 B0 32 40 40 C0
  40: 13 00 98 32 11 00 00 1E  00 00 00 FD 00 38 4B 1E
  50: 51 11 00 0A 20 20 20 20  20 20 00 00 00 FC 00 53
  60: 79 6E 63 4D 61 73 74 65  72 0A 20 20 00 00 00 FF
  70: 00 48 53 48 4C 38 30 30  30 34 38 0A 20 20 00 98

Display adapter
  Adapter description......... NVIDIA GeForce 6800 Series GPU
  Adapter device ID........... 0x00F910DE
  Display settings............ 1600x1200, 32bpp

User/computer information
  Registered user name........ n/a
  Registered organization..... n/a
  Network user name........... James
  Network computer name....... RACER
  Windows version ............ Windows XP
  Windows build .............. 5.01.2600 Service Pack 2
  Installation date .......... 29/07/2004 12:00:00

[Rik Wang]

That is the analog EDID your MonInfo report is showing. The digital EDID will be different.

One thing to be aware of: the analog EDID is asking for 162MHz of video bandwidth to display 1600x1200, and the max for a single link DVI connection is 165MHz.

You should post the didgital EDID report from MonInfo...

[endeval]

Thanks Rik.

This is it (I didnt reboot, I just reconnected the DVI cable).


It may be coincidence, but it seems the screen flashes alot of more when white or bright objects, eg windows are open. I have a dark background.

Many thanks in advance
James.

Monitor
  Windows description......... SyncMaster 204T/204Ts/204B,SyncMaster Magic CX201Ts(Digital)
  Manufacturer description.... SyncMaster
  Manufacturer................ Samsung
  ?
  Plug and Play ID............ SAM01AE
  Serial number............... HSHL800048
  EDID data source............ I2C bus (real-time)
  ?
  Manufacture date............ 2006, ISO week 32
  EDID revision............... 1.3
  Display type and signal..... Digital
  Sync input support.......... n/a
  Screen size................. 410 x 310 mm (~22")
  Power management............ Active off/sleep

Color characteristics
  Display gamma............... 2.20
  Red chromaticity............ Rx 0.640 - Ry 0.330
  Green chromaticity.......... Gx 0.300 - Gy 0.600
  Blue chromaticity........... Bx 0.150 - By 0.060
  White point (default)....... Wx 0.313 - Wy 0.329

Timing characteristics
  VESA GTF support............ Not supported
  Horizontal scan range....... 30-81kHz
  Vertical scan range......... 56-75Hz
  Video bandwidth............. 170MHz
  Extension blocks............ n/a
  Timing recommendation #1.... 1600x1200 at 60Hz
      Modeline................ "1600x1200" 162.000 1600 1664 1856 2160 1200 1201 1204 1250 +hsync +vsync

Standard timings supported
   640 x  480 at  60Hz - IBM VGA
   640 x  480 at  67Hz - Mac II
   640 x  480 at  72Hz - VESA
   640 x  480 at  75Hz - VESA
   720 x  400 at  70Hz - IBM VGA
   800 x  600 at  56Hz - VESA
   800 x  600 at  60Hz - VESA
   800 x  600 at  72Hz - VESA
   800 x  600 at  75Hz - VESA
   832 x  624 at  75Hz - Mac II
  1024 x  768 at  60Hz - VESA
  1024 x  768 at  70Hz - VESA
  1024 x  768 at  75Hz - VESA
  1152 x  864 at  75Hz - VESA
  1152 x  870 at  75Hz - Mac II
  1280 x  960 at  60Hz - VESA
  1280 x 1024 at  60Hz - VESA
  1280 x 1024 at  75Hz - VESA
  1600 x 1200 at  60Hz - Samsung
  1600 x 1200 at  60Hz - VESA

Raw EDID base
  00: 00 FF FF FF FF FF FF 00  4C 2D AE 01 30 32 52 42
  10: 20 10 01 03 80 29 1F 78  2A EE 95 A3 54 4C 99 26
  20: 0F 50 54 BF EF 80 A9 40  81 80 81 40 71 4F 01 01
  30: 01 01 01 01 01 01 48 3F  40 30 62 B0 32 40 40 C0
  40: 13 00 98 32 11 00 00 1E  00 00 00 FD 00 38 4B 1E
  50: 51 11 00 0A 20 20 20 20  20 20 00 00 00 FC 00 53
  60: 79 6E 63 4D 61 73 74 65  72 0A 20 20 00 00 00 FF
  70: 00 48 53 48 4C 38 30 30  30 34 38 0A 20 20 00 25

Display adapter
  Adapter description......... NVIDIA GeForce 6800 Series GPU
  Adapter device ID........... 0x00F910DE
  Display settings............ 1600x1200, 32bpp

User/computer information
  Registered user name........ n/a
  Registered organization..... n/a
  Network user name........... James
  Network computer name....... RACER
  Windows version ............ Windows XP
  Windows build .............. 5.01.2600 Service Pack 2
  Installation date .......... 29/07/2004 12:00:00

[endeval]

Wait a minute.....I just noticed something...

  Screen size................. 410 x 310 mm (~22")

Its a 20inch, not a 22 inch ?!?!

[Rik Wang]

The size in inches is just an approximation made by MonInfo - the exact size is in mm.

As you can see, the bandwidth wanted for 1600x1200 is very close to the absolute maximum DVI supports, so that could be it. It could also be the cable (too long? cheap?), resulting in signal dissipation.

Finally, it could be - not your particular card - but NVidia's integrated TMDS itself, on the 6800.

The fact that it happens at 1600x1200 but not 1280xx1024 suggests its the extra bandwidth required...

[endeval]

Hi Rik,
Thanks for that.

I tried Samsung's own DVI cable shipped with the unit, which I would have hoped to be designed to be good enough for its own monitor.  I also used a Belkin Pro cable and the results are effectively the same.

I had opened a call with nVidia and they said its a bad DVI port on the 6800 which I dont actually believe.  Unless nVidia are trying to advoid admitting to poor TMDS chips in their 6xxx cards?

What is the max bandwidth of DVI ? 165mhz?

Many thanks

[romain]

I also have a blinking (or "flickering") SyncMaster 204B.  The same computers (connected through a 4-way DVI KVM) worked just fine with a Dell 2001fp, but right now the ATI video boxes blink, and a box with an eVGA 6200LE is perfectly happy.  Another forum has observed the same problem and apparently it's a product defect:
http://www.evga.com/community/messageboard/post.asp?method=TopicQuote&TOPIC_ID=19835&FORUM_ID=32.
(hope that URL works...)

[endeval]

Many thanks for the info Romain.

[endeval]

I have just noticed in the quick start guide for the monitor ;

Setting the veritcal frequency
The vertical frequency can be limited by the capacity of the system.
Recommended refresh rate: 60hz (if the maximum resolution is applied, set the vertical frequency at less than 60Hz.)


HUH?  I am running the monitor at max res, 1600*1200.  Can I set the vertical refresh less than 60Hz?

[Rik Wang]

Of course you can. PowerStrip menu > Display profiles > Configure > Advnaced timing options.

[endeval]

Thanks Rik.

I set
Horizontal Scan rate 70Hz
Vertical Refresh rate 56Hz

Leading to a Pixel clock of 151.200Mhz.

This has vastly improved matters when using DVI.  The monitor only blinks about once every 3/4 minutes.

I would still think its a Samsug issue, no?

[Rik Wang]

I would be inclined to think its a 6800 DVI issue...

[domski]

I think this is a problem with the Samsung 204B monitor.

Running 1600x1200, using a DVI connection, the display switches on and off at random, and I get intermittent "not recommended mode" warnings.

I am using completely different software and hardware.  I'm running Linux, and have tried two different video cards, different DVI cables, different monitors (I have two screens and get the same problem with whichever screen I connect to with the DVI cable).

XOX DOM

[domski]

I think this is a problem with the Samsung 204B monitor.

Running 1600x1200, using a DVI connection, the display switches on and off at random, and I get intermittent "not recommended mode" warnings.

I am using completely different software and hardware.  I'm running Linux, and have tried two different video cards, different DVI cables, different monitors (I have two screens and get the same problem with whichever screen I connect to with the DVI cable).

XOX DOM