HP15C displays gibberish. Is it broken?

[sebi]

(10-06-2020 05:56 PM)GreyUser Wrote:  ... if you have Tony Duell’s schematic...

Could you point me to the schematic you are talking of please?

(10-06-2020 05:56 PM)GreyUser Wrote:  The display pattern shown on the failed unit of the OP is a processor/r2d2 comms failure...

As a newbie, can you help me with the jargon: OP? r2d2? comms stands for communications, right?

(10-06-2020 05:56 PM)GreyUser Wrote:  Due to the way the display is multiplexed ... you could never create that exact display with a loss of connections

Very interesting~~