The voltages mentioned all look OK. Should be fine for U451/U452 as it's well within operating limits.
I'm too lazy to look at the manual at the moment, but from memory, U541/U452 are just buffering video output data, so nothing too critical. They'll be running from the video supply, which is just a separate +5V supply from the rest of the logic.
As for the chip memory, just use what's listed to work correctly.
Just because you're getting a green screen labeled as "chip memory error", there are a number of other things which can cause the same problem which is not related to chip memory. A bad CIA, for example, can produce the same thing.
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This went a bit over my head
Can you explain the "plated through hole tech" ? And as for "solder shorts", do you mean because the holes are too close? I've been very careful, testing with my DMM to make sure there are no shorts.
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Plated through hole (PTH) simply means that the walls of the holes drilled in the PCB for component legs to be soldered in, are plated with copper. So instead of having just a top and bottom pad with a hole in the fibreglass, the top and bottom pad are joined together with a tube shape of copper around the outside of the hole. The tube is chemically plated in during PCB fabrication.
They're good at creating incredibly strong, reliable and vibration proof joints for leaded components. Connections which are conveniently compromised by using crappy dual-wipe IC sockets.
The down side to PTH is it's a lot harder to unsolder components from.
Solder shorts can sometimes be caused from a "hair" of solder bridging two pads together. Sometimes by applying too much solder as well. For some reason, people have the idea that using an entire roll of solder for each joint will make it more reliable or something?! You only need enough to just fill the hole.
Luckily, the component lead pitch used in the A3000's board technology (2.54mm) is so large (far apart) it's quite hard to cause accidental shorting. You could probably still get reliable soldered joints from a blind gorilla weilding a flame thrower.
Actually, I've just been working on some boards which appear to have been soldered by such a beast, but that's another story...
Good luck with the A3000 repair. The only thing you can easily do is measure/repair any damaged tracks/vias around the battery area, and replace any corroded sockets and ICs.
Make sure you haven't done anything silly in the process. I've seen it before where people pull out ICs to reseat them, but end up bending pins when re-inserting them into sockets, so the legs bend up or get broken off.
