10 Digit Scientific Calculator: Defective: Hardware Hacking [COLUG]

[jep200404]

Whatever you do, have fun with it. 

Mark Erbaugh wrote:

> We bought a unit for evaluation and the one we got was defective. 
> One segment was out of each of the LCD digits (probably a bad
> solder joint to the LCD panel). 

Connections to LCD panels are rarely done with solder. 
Usually, a "zebra strip" is used. 

   http://www.zaxisconnector.com/Z-Carbon-LCD-Elastomeric-Connectors.shtml

Explore. 

If you don't exchange it for a new one, 
take it apart and play with it. 
Fortunately, it's held together with screws, 
which makes it easy to take apart and put back together. 
Take a picture of it _before_ taking it apart, 
so you'll know which buttons go where. 

Be gentle. 

If you're lucky, you'll spot some obvious assembly blunder 
and fix it by reassembling it correctly. 
Be gentle screwing the case back together. 
The screws strip the case plastic too easily. 

Be clean. 

Try not to touch any electrically mating 
surfaces (contacts). The oil from your fingers can cause 
contacts to become intermittent. 

> We also found that by applying slight pressure to the case near 
> the panel we could affect the display. 

I've seen old abused calculators do this. 

Sometimes, they could be fixed by unbending them. 
Sometimes, disassembling and reassembling them. 

At worst, you'll get two almost new AG13 batteries.