[Kevin Kuehn]

When you had the IF aligned to 24.3MC, did you try adjusting the oscillator slug for channel 3 (Sams reference A19) while you had your DVD player playing through the rf modulator? Also A8 is the master oscillator adjustment that will offset all channels equally. If you look at the schematic you will see A8 is a trimmer cap in parallel with the fine tuning control. A9-A20 are the individual slugs for each channels oscillator coil. Those adjustments combined are what sets the correct oscillator frequency that in turn is mixed with the input rf, and is sent into the video IF. Another possibility is that if someone had the tuner coils out they may have gotten them mixed up and not installed back in the correct order, in which case channel 3 may not really be creating the correct oscillator freq for channel 3.