Editing Super Famicom Maintenance Guide (section)

=== Nintendo's colour-fault tree ===

Nintendo's own sequence, worth following because it separates the RF path from the direct video path early.<ref name="nintendodiag" />

* '''Monochrome picture.''' Check the oscillation frequency. If it cannot be adjusted or will not hold, replace TC1, then X1.
* '''Only the RF output is wrong.''' Replace the RF modulator.
* '''Both RF and direct outputs are wrong.''' Inspect the discrete components around the RGB encoder (U7) for solder defects and damage, then replace U7, then PPU2 (U3).
* '''Colour cast — reddish, bluish and so on, on RGB, S-Video and composite together.''' Probable causes are a defective PPU2 or a missing or interrupted red, green or blue signal out of the RGB output. Check around the transistors that amplify the RGB signal (Q3 to Q9) for solder defects and damage, then replace PPU2 (U3).
* '''Only the BG6 image signal is normal.''' Probable causes are a defective RGB encoder or defective colour signal filters at C14 and C16. Inspect the discrete components around U7, then replace U7.