I have the same problem. I get a box with "not optimum mode. But what I need is a picture of the mainboard with the 50 ohm resistor between pin5 and pin6.

hello
I am a technician-informatic. I have repaired about 80 Lcd Samsung monitors with theese problems. I offer the repair manual.
Manual has been done with the experience of the repairing Samsung Lcd monitors. Manual was made by me and shows how to open monitor, how
to solve dark screen problem, how to check and replace capacitors, how to solve the problem non-optimal mode (without reprogramming MCU or
changing the main board) photo are included. 100% functional. The repair process is very simple 30-40min. (does not need a lot of
experience in electronics and expensive instruments) and is not expensive. With this manual you can solve problems by yourself and save
money.

"Not Optimum Mode 1280x1024 60Hz"
- The monitor turns on but turns off by itself, the LED blinks green.
- If you detach from the PC points to "control cable" the picture runs continuously in the vertical direction or presents while line , and
as soon as it is reconnected, the monitor goes off.
- The monitor does not turns on and dont dispaly anything, the LED blinks green-lit, if you detach from pc points to "control cable".
- The monitor turns on, works well some time, but after a window apiers "Not optimum mode. Mode recommended 1280X1024 60Hz"
- The monitor turns on, works well only with low resolution 800x600, when try to change a window that reads "Not optimum mode. Mode
recommended 1280X1024 60Hz"

the manual you can find on ebay (my ebay name is asnerejas123):
Samsung monitor repair manual guide 710n,913v,510n more
220498646211
Riparazione - repair Lcd Samsung monitor 710n,913v,510n
220498645860
Reparaturhandbuch für Samsung 710n,913v,510n und