Found these inside a non-working 71B

[rprosperi]

(03-11-2018 01:45 PM)MikeSD Wrote:  1) I have a couple versions of the museum DVDs if I can find them but I don't recall a schematic. What doc was that in?

3) Any idea what the buzzer mod is for?

For 1), you probably want to use the "HP-71B Hardware Internal Design Specification (more complete, 164 pages)" document. It contains schematics, board layout, etc. although it is not a full-blown service manual.

For 3), often, buzzers were replaced/modified to make then louder for use outdoors, such as surveying, and also in factory settings. Not sure if these apply here, just a guess.

For 2), I hope Paul is still reading... lol