I've been looking into the service manual, and looking up the most convenient connection point to U421C pins 25/26, like any associated components connected to each of those pins. where it should be easy to hook the scope probe to.
According to the component locator list, IC421 is located at location 3F on the A10 board component layout. Located.
Turns out pin 25 is connected to R447, R448, and C447. I've also located those components already in the same 3F area.
Pin 26 is connected to R432, R445, C432, and C444. But these components are supposedly located at area 2L of the board.
But I am unable to locate any of these components at 2L, perhaps a mistake in the manual? Also looked at 3F around IC421, where I would rather expect them to be, but don't see them there either.
And it does not help that in both copies of the service manual that I have, the A10 board component layout is quite low resolution.
So at even at 3:1 mag it starts to get grainy which makes it difficult to read the component labels.
My SM copies came from the links posted earlier, which turned out to be the ones I already had on file.
Anybody have a better resolution image of A10 component board layout?
