I picked one these and it has LED's 13 threw 16 lit in the test mode
all the time. Problem points to U6. Quad 2 Input NOR Gate. TI SN4467,
HP 1820-0328.


When the output is low the Led lights up.


It looks like the replacement would be a SN7433, Quade 2 input NOR with

open collector.


Can someone conferm this.


Dose anyone have a cross reference to the HP IC part numbers for this
model?


Thanks


RJ