Radio Shack Portavision (color CRT) suddenly died, dark out-of-focus image

[Findm-Keepm]

Originally Posted by mrjukebox160

Bad CRT. Broken pin in CRT seal.

The area looks external to the CRT - possible conductive white RTV sealant. Sony and others used it for isolation of the focus pin, but the RTV gets dirty with dust over time and the combination of HV and dust leads to problems. Sony had the tech take off the RTV coating between the plastic CRT base and the CRT, and use their part-numbered RTV sealant. We used RTV3145 or GC's Silicone Sealant for Electronics with 100% success.

http://knobsandpots.com/images/TVP0557.pdf

I'd get rid of the White and black sealant in the areas pointed at.