Texas Instrument TI Programmer

Often during the week ends we love to visit antique malls and similar places, looking for something to adapt to other uses or just strange things.
Sometimes instead I found things that .. well, something I can not just leave there.

Last weekend I found a 1977 TI Programmer !!!
A calculator made for programmers, more or less at the time I was starting my first step in the field !

   

Amazingly the unit is basically like new !
No scratches, well preserved, no fading keys or plastic and it works just fine .. providing a 9 V battery instead the battery pack coming with the unit.

Of course the only thing not working is the rechargeable pack.

In theory should be enough to clean up the contacts and change the two batteries to have back the battery pack, but it could be little bit more complicated.
A quick search showed up this website : DATAMATH PICTURES.
Looking at the pictures my battery pack seems to be BP8 or BP9 model.
Further research brought me to this place : Battery pack technology
It explains very well how the BP8/9 model works and the possible problems.
And here I found what possible AC charger is needed for this battery pack, an Adaptor AC-9132, capable to provide 5.7 Volt with  240 mA output.

So in order to repair the battery pack the first step is to change the two batteries, connect an AC source to charge the batteries and see if the battery pack come back to life.
If not, the converter need to be replaced, hoping the guy still sell the converter.

Stay tuned for updates :)

Starting repairs (September 2018 update)

OK, time to assess the situation.  First, I was able to order an original AC charger on Ebay.
Good.
Then I took apart the BP-8 and assess it's state.
Not good.
The batteries of course are just trash now, but the oxidation, in part caused by the battery chemical, damaged quite badly even the PCB.
Here the converter removed from the box.

The oxidation is quite visible especially on the left.
As first attempt I did try to remove some oxidation with a nice bath in .. vinegar.
After placing the entire circuit in a glass filled up with vinegar (lot of bubbles !) with a soft toothbrush I started to clean gently the PCB.

Above the PCB after the bath in vinegar and a well rinse with distilled water.
The copper traces are still there but exposed and the solder is really a mess.
I did try to redo some soldering (on the right) but the oxidation below the surface is awful.
The chip pins are still there but I doubt there is a good contact and actually I think they are even corroded in part. The same goes for the other components.
Here a magnified picture of the area :

I'll try to redo all the soldering with higher temperature and a good solderer and then I'll try to connect two new batteries and see what happens.
Probably some nice smoke :)

Stay tuned for updates :)

November 2018 update

No luck so far. The PCB is really damaged and the IC doesn't seems in better conditions.
I did try to contact a guy that did offer a replacement but no luck, no answers so far.
Need to evaluate alternatives.