CRT:Disabling Velocity Scan Modulation

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

Smaller sets (20" and smaller) and the S series do not have VSM. It appears that turning off the Color Killer feature (KOFF) also turns off VSM.

• BA-5D chassis (e.g. KV-36FV310): Turn off "ClearEdge VM" in the user menu. Alternatively, you can change "KOFF" to 1 in the service menu, save it, and turn your set off and back on.
• BA-4D chassis (e.g. 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.
• FE-2 chassis: (e.g. KV-25FX30, KV-29FX30): Since there are no options to turn it off in either the user menu or the service menu, you need to disconnect the third pin—"VM VCC" (counting from the bottom)—on CN1701 of the VM board. The "Movie" picture preset also sort of disables it, but it prevents you from adjusting brightness, color, and sharpness. That’s why disconnecting the "VM VCC" pin is a better solution.

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

Illustrations

Sony

• FE-2 chassis | KV-25FX30 / KV-29FX30

Page from the "KV-25FX30 / KV-29FX30" service manual, showing the VM schematic, CN1701, along with some added photos to help identify the correct pin, etc.