HP15C displays gibberish. Is it broken?

[BillBee]

(10-06-2020 05:56 PM)GreyUser Wrote:  No clock in a voyager results in blank display. Every time.

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The display pattern shown on the failed unit of the OP is a processor/r2d2 comms failure, any number of causes. If a reset doesn’t fix it, it’s most likely a bad r2d2.

It is not bad LCD contact. Due to the way the display is multiplexed, regardless of the differences between the original 3:1 and the later 4:1 mux schemes, you could never create that exact display with a loss of connections, it’s physically impossible as the missing segments are common with segments that are in fact displayed.

Thank-you for that explanation.

-Bill