Resolution can't go higher than 1280x1024 - native is 1920x1080

Question

This seems to only be a problem in Snow Leopard, as it works fine as a display for a Windows PC. I try to attach my Samsung SyncMaster to my mac and the maximum resolution it says it accepts is 1280x1024@60 or 70Hz. Its native resolution is 1920x1080@60HZ. I've tried SwitchResX, and when I try to install this resolution it comes back with "Not activated - Invalid?"
Is there a way by editing a file I can change or force the resolution in terminal or a file to edit the external display's resolution (iMac 2009 Snow Leopard) I've got 10.6.2 ... any help is appreciated!
Thanks in advanced!
This is only the mini displayport to dvi adapter

Answer 1

This is what the file says:
What should I do with it? Edit what and save it where to take effect?
{quote:title=Syncmaster File Contains:}
DDC block report generated by SwitchResX version 4.1.1 for display
SyncMaster
------------------- RAW DATA ------------------------
0 1 2 3 4 5 6 7 8 9 A B C D E F
0 | 00 FF FF FF FF FF FF 00 4C 2D 61 01 00 00 00 00
1 | 14 0E 01 03 80 22 1B 78 2A EE 91 A3 54 4C 99 26
2 | 0F 50 54 BF EF 00 81 80 01 01 01 01 01 01 01 01
3 | 01 01 01 01 01 01 64 19 00 40 41 00 26 30 18 88
4 | 36 00 52 0E 11 00 00 18 30 2A 00 98 51 00 2A 40
5 | 30 70 13 00 52 0E 11 00 00 1E 00 00 00 FD 00 38
6 | 4B 1E 51 0E 00 0A 20 20 20 20 20 20 00 00 00 FC
7 | 00 53 79 6E 63 4D 61 73 74 65 72 0A 20 20 00 FD
< 00FFFFFF FFFFFF00 4C2D6101 00000000 140E0103 80221B78 2AEE91A3 544C9926 0F5054BF EF008180 01010101 01010101 01010101 01016419 00404100 26301888 3600520E 11000018 302A0098 51002A40 30701300 520E1100 001E0000 00FD0038 4B1E510E 000A2020 20202020 000000FC 0053796E 634D6173 7465720A 202000FD >
Valid EDID block: checksum passed
------------------- MAIN EDID BLOCK -----------------
EDID Version........1.3
Manufacturer........SAM
Product Code........24833 (6101) (0161)
Serial Number.......00000000
Manufactured........Week 20 of year 2004
Max H Size..........34 cm
Max V Size..........27 cm
Gamma...............2.20
Display Supported Features:
Power Management: Active off
Display type:
RGB 4:4:4 & YCrCb 4:4:4 Color Encoding Formats
Display is non continuous frequency
Default color space is not sRGB standard
Preferred timing mode includes Native Pixel Format
Input signal & sync:
Digital Input
Color Bit Depth is undefined
Digital Interface is not defined
Color info:
Red x = 0.640 Green x = 0.300 Blue x = 0.150 White x = 0.312
Red y = 0.330 Green y = 0.600 Blue y = 0.060 White y = 0.329
Established Timings:
720 x 400 @ 70Hz
640 x 480 @ 60Hz
640 x 480 @ 67Hz
640 x 480 @ 72Hz
640 x 480 @ 75Hz
800 x 600 @ 56Hz
800 x 600 @ 60Hz
800 x 600 @ 72Hz
800 x 600 @ 75Hz
832 x 624 @ 75Hz
1024 x 768 @ 60Hz
1024 x 768 @ 70Hz
1024 x 768 @ 75Hz
1280 x 1024 @ 75Hz
Manufacturer Reserved Timings:
Standard Timing Identification:
#0: 1280 x 1024 @ 60Hz (8180)
Monitor Description blocks:
Descriptor #0 - Timing definition:
Mode = 1024 x 768 @ 60.004Hz
Pixel Clock............. 65.00 MHz Non-Interlaced
Horizontal Vertical
Active.................. 1024 pixels 768 lines
Front Porch............. 24 pixels 3 lines
Sync Width.............. 136 pixels 6 lines
Back Porch.............. 160 pixels 29 lines
Blanking................ 320 pixels 38 lines
Total................... 1344 pixels 806 lines
Scan Rate............... 48.363 kHz 60.004 Hz
Image Size.............. 338 mm 270 mm
Border.................. 0 pixels 0 lines
Sync: Digital separate with
* Negative vertical polarity
* Negative horizontal polarity
Descriptor #1 - Timing definition:
Mode = 1280 x 1024 @ 60.020Hz
Pixel Clock............. 108.00 MHz Non-Interlaced
Horizontal Vertical
Active.................. 1280 pixels 1024 lines
Front Porch............. 48 pixels 1 lines
Sync Width.............. 112 pixels 3 lines
Back Porch.............. 248 pixels 38 lines
Blanking................ 408 pixels 42 lines
Total................... 1688 pixels 1066 lines
Scan Rate............... 63.981 kHz 60.020 Hz
Image Size.............. 338 mm 270 mm
Border.................. 0 pixels 0 lines
Sync: Digital separate with
* Positive vertical polarity
* Positive horizontal polarity
Descriptor #2 - Monitor limits:
Horizontal frequency range.......30-81 kHz
Vertical frequency range.........56-75 Hz
Maximum bandwidth unspecified
Descriptor #3 - Monitor name:
SyncMaster
{quote}