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Help needed: HP 67 repair
08-26-2020, 02:29 AM
Post: #4
RE: Help needed: HP 67 repair
I still didn't study the signals, but the C segment problem seems to be related to the transistors near the display: when I removed them, segments G turned off, and segments C started to behave correctly. I'll try cleaning the board somehow, specially under the display LEDs, probably I have some kind of short between C and G lines.

And I think I have damage on the ROMs: the calculator behaves the same exact way with or without any of the 8 pin ROMs. But I'll try to investigate more and find out where exactly the problems are.

Thanks!

Eduardo
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Messages In This Thread
Help needed: HP 67 repair - Marcovecchio - 08-24-2020, 03:58 AM
RE: Help needed: HP 67 repair - teenix - 08-24-2020, 06:16 AM
RE: Help needed: HP 67 repair - Marcovecchio - 08-26-2020 02:29 AM



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