The Radio Shack EC-4019 is a great calculator. I have had it since the late 1980s since it was new. It has worked flawlessly up until about 2012, when a new battery was needed. Yup, it took over 20 years to finally have the need to replace the battery. Not to suggest that it is being used on a daily basis or even once or twice a year, however, 20 years for a battery is well how things used to be made. The same holds true with this calculator, so for a few dollars a new battery would breathe new life into it – and it did. However, the screen had an LRN at the top of the screen and a flashing IIIV and was stuck at 0 as if the keyapd no longer would respond. I chalked this up to a bad calculator and left it in the drawer for the past couple of years. Until the other day…
I was ready to toss this calculator into the trash, until I realized that maybe if lucky there would be some information on the Internet that would identify this problem and resolve it. After trying a few things, I found a solution that brought life back into this calculator.
As I would have thought, simply replacing the battery was not enough. There are more steps to this process. Follow these steps and the described behaviour will correct itself.
Replacing the battery.
- Slide open the battery compartment lid on the back of the calculator.
- Remove the dead battery
- Wipe off the new battery with a dry cloth to maintain good contacts.
- Insert a new battery with its flat side (plus terminal) on top.
- Replace the battery compartment lid.
- Turn the power on.
- Press MODE DECIMAL key SHIFT KAC AC SHIFT M in key
MODE EXP SHIFT PCL MODE 4 MODE 9 MODE 1
DEC MODE 0 MODE DECIMAL key.
The Radio Shack document continues with:
Addition, subtraction, multiplication and division are performed in the
RUN mode or COMP mode. If LRN, LR or SD is on the Display, switch to the RUN mode or COMP mode by pressing MODE and DECIMAL key and MODE 0.