To downscale down-scale to 240P you must have and do the following criteria:
Use a 480P video source to input, sources higher than 480P will not work.
Make any adjustments to the gbscontrol firmware before engaging 240 15khz output
Set the AIO board switches correctly
The only 2 analog output for the GBS-C AIO are RGBHV and YPbPr (Component). There is no support for RGBS.
If you use YPbPr (Component) output we recommend using a cables similar to one of these :
Make any adjustments to the Gbscontrol Firmware before proceeding including toggling The RGBHV/Component Toggle found in the "Preferences" tab to select the either RGBHV or YPbPr (Component) video output.
If you toggle the output to YPbPr (Component Video) set the middle switch on the front of the GBS-C AIO to "YPbPr" This puts the signal at the proper resistance for YPbPr (Component Video) output
Set the left most switch "HDMI OFF". Failure to set the switch to off will result in a dimmer image and may cause damage to the GBS8200 over time as the video driver is not made to output to more than one video source.
On the Gbscontrol Firmware "Preferences" page click the button "15KHz Scale Down"
Some monitors need to be set for YPbPr (Component Video) Mode. Consult your monitors manual for guidance.
NOTE: When Toggling RGBHV/Component, YPbPr (Component Video) mode prevents sending the correct video signal to the HDMI output resulting in a black screen. Toggle back to RGBHV mode or reset your settings under the "System" tab > "Reset Defaults + Restart" Button.