The Pickup

Well I thought it was the deal of a century, a 21″ Sony G21S1 CRT for a whole $1! I had heard these were RGB moddable and just couldnt resist having a go myself. Upon pickup it was obvious that this thing was hardly ever used and just had sat in a basement for years. I reached out to my mate Matt and asked for the run down of how he modded his and got the full photo breakdown which was encouraging.

The guts of the TV

A quick look inside and it was very dusty but also very empty, all that needed to happen was the dust be blown out and a screw post be JB Welded back on.

Adding in the RGB Mod

Now for the hard bit, essentially you can mod these by tapping into the OSD that is used for Teletext and the one screen menus etc and inject and nice clean RGB signal into it. For this model, you can tap in at the empty socket for CN104 which has R, G, B, the blanking Pin and Ground. R,G,B and ground is obvious, the blanking pin is the part that you need to concern yourself with. You need to tell the TV to turn on the OSD which takes ~3V. Even though I thought it would be 0Volts LOW and 5V HIGH it seemed to have an limit where to turn the OSD on it needed to be ~3Volts, something Matt had told me about. To do this, I just grabbed 5V from a nearby spot and used a regulator and trimpot to pull it down to where I needed it to be. You also need connect up the composite pin from the SCART plug to the onboard Composite plug to inject the CSYNC or else the machine won’t have sync.

The Final Outcome

Once all the wiring was complete I drilled and dremelled out the SCART port and added some labels and switches to enable/disable the SCART/OSD mod. It looked remarkably clear after this mod and you could see all though glorious scanlines.