Well, you seem to have gotten a kinder response than most give these days.
There's not much for solder joints to just be a common cracked joint on those though.
I didn't read back through the thread, but is this problem on a known working monitor ?
What was the other boardset doing? (the one in the shop)
My AD is not accessible at the moment, but I do have a boardset handy to look at if you question anything you see on that one.
(a spare working boardset no less)
