North American Philips C8 Chassis S-Video, Composite, & Audio Input Mod

The C8 Series Color TV Chassis is the new, high-end chassis used in 19", 20", 25", and 26" models. The 20" and 26" models feature the new generation of picture tubes that are flatter and more square than the 19" and 25" picture tubes.

Isolated chassis by North American Philips from the mid to late 80's using Philips IC's in Magnavox, Philco, or Sylvania branded sets. North American Philips was operated by N.V. Philips (Netherlands).

Composite Mod

Lift the side of inductor L202 that is closer to the IF chip, and inject composite into the lifted leg. Connect ground to a cold/isolated ground point on the chassis. If you don't get horizontal sync try a different grounding point. There is a row of unused header pins next to the IR receiver; I used pin 2 as ground.

S-Video Mod

First do the composite mod above except inject luma there instead of composite. Then lift the leg of disc capacitor C605 that is closer to the 5V regulator and inject chroma into the lifted leg. See diagram above.

Audio Input Mod

Lift the leg of resistor R245 that is closer to the IF chip but do not inject audio here. Inject audio into the leg of C279 that is further from the sound amplifier chip (do not lift). See above diagram. Connect ground to a cold/isolated ground point on the chassis. It will sound like an untuned AM radio if not grounded correctly. I repurposed the IF audio output RCA jack in the rear to be an input. I also made it take stereo and downmix it by adding a 1K resistor to each audio input jack then joining them before injecting.

Switch Between S-Video and Composite

On the model I have there is a DPDT switch on the rear jack panel that can be repurposed for switching between composite and s-video. It was for switching between cable and antenna which has no use in this mod so replace the existing wiring as shown in the diagram below.

List of C8 Chassis Sets

Listed below are just the base model numbers, of which there are many revisions/variations with different suffixes appended to the model number on the cabinet label.