litriSE's latest activity
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LlitriSE replied to the thread Mac Plus 820-0174-A: pulsating vertical-line pattern, no bong, good sync — TSM and LAG cleared via custom PAL exerciser. Where next?.Hello eifeldude! No, I have not made additional progress on this board. I plan to work on it again over the next coming weeks. I'll...
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LlitriSE replied to the thread Mac Plus 820-0174-A: pulsating vertical-line pattern, no bong, good sync — TSM and LAG cleared via custom PAL exerciser. Where next?.I pull the last three remaining chips in the jellybean section - 74LS257 U2G, 74LS393 U1F, 74LS393 U1G. The 74LS257 in U2G was bad and...
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LlitriSE replied to the thread Mac Plus 820-0174-A: pulsating vertical-line pattern, no bong, good sync — TSM and LAG cleared via custom PAL exerciser. Where next?.I continue to struggle to clear the 02FFFF error. I've replaced all four 74F253s. I also pulled the 74LS257 at U2F — it tested clean on...
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LlitriSE replied to the thread Mac Plus 820-0174-A: pulsating vertical-line pattern, no bong, good sync — TSM and LAG cleared via custom PAL exerciser. Where next?.Update: Mac Plus 820-0174-A — pulsating vertical lines, no bong Located and replaced a faulty 74F253 mux (confirmed via DMM —...
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LlitriSE posted the thread Mac Plus 820-0174-A: pulsating vertical-line pattern, no bong, good sync — TSM and LAG cleared via custom PAL exerciser. Where next? in Compact Macs.Mac Plus 820-0174-A: pulsating vertical-line pattern, no bong, good sync — TSM and LAG cleared via custom PAL exerciser. Where next? Hi...
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