Hey, i too had this problem with my monitor. The monitor keeps getting ON/OFF randomly and also i was not able to adjust the monitor setting using those buttons(micro-switch). Turned out that the micro-switches were the culprit. So, i got replaced all the 5 micro switches and now it works fine.
I took it to nearby TV repair shop and he opened the monitor front panel, removed the old micro switch and installed new one. He charged me total Rs. 150/-.
Rs. 100 as service charges and Rs.50 for the cost of 5 micro switches.
In my case, the monitor just goes OFF at random while working and after some time, it displays the picture.
So, if in your case, its working fine for some time but goes blank after some time, then its definitely the micro switches. But if its not able to display your desktop, then that might be some other issue.