Hey there I bout a philips crt rptv from a friend and I'm going to change the coolant but the colors are off horribly, the red shows to much my picture is more red than anything, the blue rarely shows but is also extremly blurry and my green bulb doesn't stay on all the time like the blue and red, wats wrong and what do I need to do to fix it thnx
Dayne

After changing my blue/green-CRT coolants recently my images were also too red. I turned down the red screen bias potentiometer slightly and that corrected it. (This pot is visible in an earlier 'guts shot' (http://www.avsforum.com/avs-vb/showpost.php?p=12593430&postcount=9). It's one of the pots on the focus block, a cigarette-pack-size board, with six red-green-blue (RGB) pot knobs just beneath the right-most lens. On my Philips you can read SCREEN or FOCUS below these 6 RGB pots.) Searching this RPTV forum for Philips or coolant or fluid reveals a number of threads covering fluid sources, procedures, etc.

If images are clear through the red lens, coolant change for the blue/green tubes may be enough. Suspect I'd change the fluids first, if I was sure they were contaminated, before tinkering with other adjustments. Normally screen bias shouldn't be adjusted since instrument-based grayscale calibration is often then required. But after adjusting both red and blue screen bias here, just slightly, B&W movies and test bars (B&W pluge patterns) appear perfect with no color tinting. -- John