I collect old video game consoles, and recently came across a TI-99/4A (without cords), so I purchased all of the necessary items plugged it in. When the boot screen first displayed, everything looked good, but it quickly (in about 5 seconds) degraded to a sort of sloppy mess. The sound quality (beeps and boops) is still good, but all of the text on the TI Basic prompt screen is unreadable.
I took pictures of the screen, the system itself, and the video modulator. The delay and gradual degradation leads me to believe it could be a bad capacitor on the main board, particularly one having to do with video display, but I figured I should ask here to see if any of you can diagnose the problem.