I am just outside of Atlanta, GA. How about you?intric8 wrote: ↑Tue Jun 02, 2020 6:43 pmFirst off - welcome!
I have seen behavior like this before. Unfortunately, it can be symptomatic of lots of things.
If you've pulled all of the cards and still have no video, I would first:
1) I've seen this exact same issue once where a machine had been told to look for a (no longer attached) drive as the boot drive in its startup sequence. For example, maybe a CD ROM player, or secondary floppy drive. Usually it's floppy first (DF0:) then hard drives, then "next drives" like a Syquest or whatever, if you've got something in the big lower bay below the floppies.
2) With the power off, I'd manually press each of the main socketed chips down to make sure they were fully seated. Sometimes during shipping or moving from place to place, something can get ever so slightly out of alignment and need a firmer connection. A solid firm press will occasionally create some popping noises, meaning a tiny chip's pin might have had a poor contact. Personally (and there are a LOT of hardware gurus here that know way more than I) I'd start with the Agnus, 68000 CPU and Kickstart ROMs. A 68000 that is dislodged will give you a black screen every time.
Do you have any DIY hack-y switches on this machine anywhere that might have gotten flipped? Are there any hardware mods (mega-chip, etc.)? Finally - is there battery damage where the batteries were soldered to the motherboard (and are they still there)?
Where are you located? Can you take and attach pics of your sick machine(s) to post here for closer inspection?