Centipede garbage on screen

chips4sle

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Ok
I have a centipede board I'm working on
I've replaced all the 2101 ram as 4 of the 8 tested bad
Also replaced the 2114 to be safe

When I press the test button I still get random 4 or 6 beeps for ram error

And the screen does this with static on it as well

The screen is white the dark is just from the camera
 

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RAM errors when you know the indicated chips are good typically means either a bus issue, or a decoding logic issue.

Check for shorts between bus lines, for all busses, to start. But it could be a bad buffer, or decoder logic chip.

Also make sure all of your clock signals are good, as well as the CPU. Start with the simple things.
 
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