Greetings,
I have 2nd revision six switch (Hong Kong?) 2600 console. I completed an composite A/V mod to the console and it works great for the first minute. It shows color for about 60 seconds, and then turns to black and white. Resetting the console and its still black and white. If I unplug the console for a while and turn it back on its color again for about a minute. Unfortunately I never tried this console with the R/F output before modding it. So unsure if the issue was also in RF mode. I have adjusted the color potentiometer , and it does adjust the color when I first turn the console on before going black and white.Things I tried to fix so far: I completed installing a "tune-up" kit from console5 that included new 7805 power regulator (old one measured fine though) caps, and even the power jack. I also installed the included 820ohm resistor between pins 6 and 9 on the TIA chip as well as the anti-static diodes on c236 and c237. I re-seated the TIA chip as well as re-flowed the solder on any suspect or cold looking joints on the board. All the switches have been cleaned and appear fine. I am at a loss. Does this sound like a defective TIA chip? I appreciate any insight to solving this! Thanks
Link to the a/v mod I used: https://www.ebay.com/itm/311653998049
I found an earlier thread with the exact same issue, but no solution was ever posted: