CRT:Disabling Velocity Scan Modulation

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Velocity Scan Modulation (VSM) is a feature for various flatscreen CRT televisions across different brands. It attempts to make the image appear artificially sharper, but can cause the image to look worse, especially with pixel art and text. Generally, it's only present in 27" and larger sets.

Disabling VSM

Sony

For later Sony sets, you can generally disable VSM in the user menu. Sets with the BA-5 chassis have it, but sets with a BA-4D chassis in the V series line (e.g. KV-27V42) require that you unplug a cable to disable it. Smaller sets (20" and smaller) and the S series do not have VSM.

  • BA-4D chassis (KV-27V42, KV-27V66): Change "KOFF" to 1 in the service menu, save it, and turn your set off and back on. Alternatively, you can unplug the cable connected to CN942 on the neckboard.
  • BG-3S chassis: Change "VMC" to 0 in the service menu, save it, and turn your set off and back on.

Toshiba / JVC / Orion

20" and larger sets likely have VSM and must be disabled by unplugging the three-pin cable on the back of the neckboard. A video showing the correct cable can be found on CRT Autist's channel.

  • On a Toshiba 20AF44: Unplug CPD852 on the neckboard (or CPD852B from the tube)

Comparison Images

VSM Comparison 1.jpg
VSM Comparison 2.jpg
VSM Comparison 3.jpg
VSM Comparison 4.jpg

VSM Comparison On.jpg VSM Comparison Off.jpg