My mistake, I meant I used 2x 1A but yes, good thinking on harmonics, swapped the 7805's back and no difference. +5V though is noisy though.
I pulled C4 to see if that made a difference and it did but I had also unplugged the video connector. When I plugged this back in prior to putting in a new capacitor, FS shrank immediately.
Removed the socket and gave the PCB some TLC and it now seems to run ok. With HS and FS on this connector its possible it was tracking, the socket on the video connector was (like the rest of the board) very badly soldered and it appears there was some strange tracking across pins.
Its not perfect as the screen is a bit noisy but at least it appears to be stable. The board hasn't been hacked about but whoever built it from a kit, used very poor quality solder and/or flux. It would benefit from removing everything and rebuilding but I haven't got time for that![:)]( "Smile")
I pulled C4 to see if that made a difference and it did but I had also unplugged the video connector. When I plugged this back in prior to putting in a new capacitor, FS shrank immediately.
Removed the socket and gave the PCB some TLC and it now seems to run ok. With HS and FS on this connector its possible it was tracking, the socket on the video connector was (like the rest of the board) very badly soldered and it appears there was some strange tracking across pins.
Its not perfect as the screen is a bit noisy but at least it appears to be stable. The board hasn't been hacked about but whoever built it from a kit, used very poor quality solder and/or flux. It would benefit from removing everything and rebuilding but I haven't got time for that
Statistics: Posted by Gary C — Tue Nov 12, 2024 7:14 am