Garatuzo

Hi guys, Thanks for your kind responses, I've been doing some tests with no success, let me explain: I used contact cleaner on the pot turning back and forth with no noticeable effect in image. Multimeter reads around 800k ohms no matter pot's position I take that reading from the two lower legs of the pot. I noticed the pot is rated 300k maybe that's it? Or my measurements were wrong? I found attached diagram online it seems to be only four transistors as part of the video circuit any advice how to test them? I have multimeter and oscilloscope if needed. After more testing RF is working in B&W as well. I've tested continuity between controller pins and the first leading trace I found on circuit everyone seems fine. Should I test Pokey chip? How? 😃 I notice some U15 pins suspicious I'll take a closer look. Yes all of them seem to work. I took some measurements as follows: U15 - 4.95V C13 - 4.95V Should I test any particular point? How could I perform further tests on Pokey, U16/14? No luck with that one bro. Thank you again for all your time and help. JC

Hi guys, I recently got an Atari XE in very nice cosmetic shape but it has two problems: -Fist, it lacks color it only displays B&W image using composite, when I try using RF it wont even show anything. -Second one, upper controller port is not working. After disassembly I can not see any obvious damage, cut trace or corrosion, any guidance to diagnose the problem would be greatly appreciated. Regards, JC