Panasonic CT-20SL15

Eli Krause
September 8, 2024, 9:33 am
October 2, 2024, 5:49 pm

Summary

Panasonic outsourced manufacturing of the CT-20SL15 to Orion, unlike the previous model the CT-20SL14J, which they themselves manufactured.

Literature

Notes

Color temperature adjustment has been removed as an option from the user menu, and so white will skew blue by default unless one adjusts the white balance in the service menu. The prior model had dedicated Menu and Action buttons on the set itself, but those have been removed so now one must press both of the volume buttons at the same time for bringing up the menu and selection.

Holding 'Volume -' on the set and 6 on the remote will display the total number of hours in operation in hexadecimal. Holding 'Volume -' on the set and 9 on the remote will access the service menu. Entering the service menu will reset the user menu picture settings to default, so you may want to write down their values first. Horizontal size is not adjustable. After being unplugged it forgets what input you were on last, but inputs can be selected with the channel buttons. This set does not have velocity modulation, unlike the 27" version.

The unified Panasonic jungle/comb filter chip in the prior model was replaced by a Renesas jungle and a Toshiba comb filter.

Composite 240p Performance

by Eli Krause

For composite decoding this set uses a Toshiba TC90A45FG, a dynamic 2-line digital comb filter introduced in 1997. Depending on the console/revision, dot artifacting ranges from moderate to severe, blending effects may be broken, and edge artifacts are mostly moderate to severe. An example of the many dot artifacts are highlighted in the second picture below in red. Using an external notch filter to decode composite instead (such as is available in a RetroTink 2X, 5X, etc.) and sending that to the component input would blend all dithering patterns, reduce edge artifacts, and remove the dot artifacts.

Toshiba-TC90A45FG-2

tosh-gen3

TOSHIBAGOOGLESHEET

Service Notes

Like some Toshibas also made by Orion, this model is extremely prone to vertical foldover due to C407 going open, 100μF 35V. It is a simple fix; a photo of this capacitor is highlighted in the gallery below.

Gallery

Panasonic CT-20SL15 Panasonic CT-20SL15 Panasonic CT-20SL15 Panasonic CT-20SL15 Panasonic CT-20SL15 Panasonic CT-20SL15 Panasonic CT-20SL15 Panasonic CT-20SL15