TI SR-52 restoration problem

[M. S.]

Hi All,

Recently I obtained a TI SR-52 calculator that look still in pretty good shape. The only thing is I have to rebuild the batttery pack as was to be expected.

I already connected the calculator to external recheageble battery pack and the leds did not light up. Also with charger attached no sign of life.

What would be the first things to check for malfunction or defect in order to find out if this calculator can be brought back to life or not...

Does anyone have experience in this, or a check list of frequntly occuring issues related to that?

Please let me know so i can try to revive this beautiful piece of history :-) 

Thanks, Mirko  

[osa...@gmail.com]

The charger should not be attached to these calculators without a battery pack installed, IC damage can result. Have you seen this page, <http://www.datamath.org/Sci/WEDGE/SR-52.htm>, adds a little background. I have some more info on these, but can't get to it right now. I have two that also show no signs of life.

There are two versions of the main board, I think. Do you have access to a logic analyser and scope? I only have a simple scope. I would start checking the voltages at the ICs. Hardware manuals are available for this calculator.

Maybe this is the spur to get me back to looking at my two, the complexity makes them a bit daunting!

[osa...@gmail.com]

<http://www.decodesystems.com/TI_SR-52_Troubleshooting.pdf>

[osa...@gmail.com]

<https://www.hpmuseum.org/forum/thread-2804.html>