Help with "no bus activity"

[bebrown]

I am assembling a few of these as VGA adapters. One of them works, but the other two display a test screen with the message "No Apple II bus activity."

What triggers this message to appear?

[buserror]

Basically, it means you need to to take you super high power loupe and check the soldering on these level shifters. And just don't trust your eyes, re-apply heat to each pins too. If you see that pattern, it's 'likely' the one on the right (the one that doesn't do data or address) has a bridge or is not soldered properly. If you then get a 'random pattern text video' it's more likely to the the ones on the left center (these 2 with data+address).
I consider myself 'very experienced' in SMT soldering, but these TSSOP packages are an absolute royal PIA!

[dkgrizzly]

The message appears when you power up the card and it doesn't see any reads or writes. That screen is meant as a test of the VGA output, and to get the Pico's serial number. I would suggest checking the orientation and soldering of the bus translation chips, paying close attention to the right most chip of the 4 (closest to the back of the Apple II when installed). That chip buffers the PHI0 clock and the R/W lines which are needed for the card to detect any activity at all.