HP 71b repair advice - won't power on with batteries or on AC adaptor

[dmh]

(06-07-2021 12:29 PM)Etienne Victoria Wrote:  Depending on your Hp71B, you might find two (as far as I know) different versions of the 71B innards :

- Earlier models with a reliable (on my units) soldered flex cable: I would advise to repair these with an appropriate flex cable.

- Later models with the cost saving, not soldered, el cheapo, plasticky, Hp41-like, so-called "Zebra" strip : these have less clearance to insert and fold a flex cable so I would advise to solder top to bottom wires directly.

Below a couple images, to show the different layouts.


V1: https://1drv.ms/u/s!Aj6GqoriKYJuhYMkhkcT...w?e=bg2jgD

V2: https://1drv.ms/u/s!Aj6GqoriKYJuhYMlFEoK...w?e=sUkf41

The latter has this prone-to-fail connector inbetween the two halves :

http://etiennevictoria.com/Titan_zebra/grand-1.html
http://etiennevictoria.com/Titan_zebra/grand-2.html


Etienne

Thanks. I think that’s the difference between the metal back and plastic back or is it not that simple to identify?

Unfortunately I can’t see the images you’ve attached. A common issue I find here. I’ve tried different browsers but no luck.