Question about SM124 Monitor

[KontraXIII]

Hi All,

 

I was recently given a box boxes of Atari ST goodies and within it I found a working SM124 monitor. It has a metal switch on the back which looks like it has probably been put on by someone. The guy I got it from doesn't know what it does so I was hoping someone here may know?

 

When I switch it the Atari reboots, one way it will work as a high res black and white monitor and the other it shows a blank screen.

[+DarkLord]

Huh, that looks odd.

 

I guess I'd (carefully! watch your voltages) take it apart and see what its hooked up to.

[ParanoidLittleMan]

There was solution with switch where you could watch ST low or medium res. on SM124. Of course as B&W. Maybe it is it.

You could see it by checking connector for Atari - if it is not original, and has RGB lines connected, then it should be it.

[KontraXIII]

I opened it and found that the switch goes to GND between Video and Audio shown in the picture. Does anyone know what this would do when switched?

[ctirad]

Look inside the DIN connector. I bet the GND wire is soldered to the pin 4 which tells the ST which kind of monitor is connected. Someone just wanted to switch between SM124 and TV without unplugging the cable.