OK- I followed some online wisdom for testing out a few boards.
Pull the (E)PROMS, boot up, look for 16 vertical (horizontal for SI) bars across the screen.
Well, I get what looks like 16 repeated 'sections' across the screen. There isn't a single solid line from one side to the other, but all the repeated 'sections' look the same.
I pulled the other trick and momentarily grounded pin 7 on each RAM chip. When I do that, a thin segment of each section goes solid white. I assume this points to bad RAM?
The RAM is a little pricey- over $1 per chip at 16 chips per board. I've got 5 boards (3 good candidates).
Has anyone replaced the RAM with something a little more modern? Single supply stuff versus the old 3-supply chips? The RAM is dead cold, but the voltages are right on. Do you think this means they were zapped at some time?
Is this common? Three boards pretty much do the same thing...
Kerry
Pull the (E)PROMS, boot up, look for 16 vertical (horizontal for SI) bars across the screen.
Well, I get what looks like 16 repeated 'sections' across the screen. There isn't a single solid line from one side to the other, but all the repeated 'sections' look the same.
I pulled the other trick and momentarily grounded pin 7 on each RAM chip. When I do that, a thin segment of each section goes solid white. I assume this points to bad RAM?
The RAM is a little pricey- over $1 per chip at 16 chips per board. I've got 5 boards (3 good candidates).
Has anyone replaced the RAM with something a little more modern? Single supply stuff versus the old 3-supply chips? The RAM is dead cold, but the voltages are right on. Do you think this means they were zapped at some time?
Is this common? Three boards pretty much do the same thing...
Kerry

