I have something that baffles me.
I am attempting to do a minor tweak to an old video game console that has a CD drive. Most games I try work OK. One in particular has to track to the very outside edge of the disc to playback a video, and it never seems to load properly. It will track out there, read for a solid 5 seconds or so, and then track inward and back outward to the same spot and attempt to read the disc again.
I imagine I can simply tweak one of the pots available in order to get it to track/read the entire disc without issues.
What is odd is that I attached my scope to one of the test pins (PCLK), grounded it to the device, powered up and two things happened:
1: I had a bit of video interference when scope was attached (no big deal)
2: The game worked!
I pulled the probe during the video playback. It finished, went to the next video, and wouldn't load. I powered down, started up again with no probe attached, and it wouldn't load.
I decided to probe a different test pin. Powered up, and it worked again. I just left the probe on there and started playing the game. It pretty much worked the entire time.
What is happening? Am I adding resistance or something with the probe hooked up to a test point that the tracking/lens is suddenly happy enough to read that track?