3yr old got ahold of monitor

We have an older computer that I had decided to give to my 5 yr old daughter so that she could play with educational programs. Well no sooner than I had it set up and running perfectly fine, I caught my 3 yr old daughter pushing on the buttons on the front of the monitor. I found the monitor black with the green light next to the power button flashing. I tried to push buttons on both the keyboard and the monitor to get it back up. The only time I receive a response is if I press and release the "MODE" or the "SELECT" buttons. I get a window that pops up that says "SELF DIAGNOSIS" across top of the box back-lit in white and underneath back-lit in blue is "PC DISPLAY SETTINGS CORRECT?" and after about 3 seconds this disappears all the while the green light next to power button is still flashing. Now if I hold the power button on tower to turn computer off since I cannot see "Start menu" on monitor then turn it back on the monitor does come on normally but it only goes as far as showing the "Microsoft Windows 98" screen then I get the cursor in the upper left as if the screen that allows you to put it into doss is about to come up. The monitor goes to the "SELF DIAGNOSIS" window that I described before and the green power light starts flashing and then screen goes blank after about 3 seconds. If you can please tell me how to correct this I would be greatly appreciative.