TI-84 Plus Calculator Bit the Dust

[Woodman]

The AAs and the coin backup battery test ok, still display does not light, no power. Can't tell if its the display or something on the main board cause I don't have a small enough torx screw to even open the dam thing. A Google search found some simple routine troubleshooting steps to try but none of those worked. Hoping you all can give me some ideas to revive this expensive calculator, when I finally open her up.


Woody

 

[Woodman]

anyone?

 

[(*steve*)]

Do you know what happened to cause this fault?

Have you tried removing the batteries, leaving them out for a couple of hours (perhaps overnight) and then replacing them with new ones?

 

[Woodman]

Hi Steve,

Don't know how fault occurred, and yes batteries were left out overnight then good batteries reinstalled as per Texas Instrument's website. TI website has only basic troubleshooting. I'm thinking bad main board or video display. Don't have parts to swap for testing, and have no clue as to how to test/repair either.


Woody

 

[Woodman]

Still don't have a star socket small enough to open this up, however I mentioned problem to a friend and he said that he has ti-85 that works but his has a few dead rows/columns. He gave it to me, but i can't open this one either (same blimy screws). This one is at least useable, if you don't mind occasionlly having to redo cause answer showed on dead pixels. Other than replacing screen, is there a fix for dead pixels on a calculator?

 

[(*steve*)]

First thing is to get the appropriate style of screwdriver!

Dead rows and columns are typically caused by some sort of failure in the connector between the LCD and the calculator.

For many displays, these are "zebra" connectors which look like a strip of rubber and are notoriously difficult to get a good connection once you have removed them or they have become misaligned via some accident.

If both are unusable, then moving the display from one to the other might be a solution, however they are not the same model and you can't be sure the panels are compatible.

 

[whiteoutage]

Five years later I finally found a screwdriver that opens this thing. A very small star bit used for phones did the trick. The common problem of bad battery to board contacts did not help as my board tests receiving 6 volts. So still nothing on screen. Thinking possibly bad tabs but I can not test voltages on board unless unit is closed so it seems impossible to do further testing? Google search on this model proved fruitless on tab repair so maybe it is too difficult?

 

[(*steve*)]

Are you sure the batteries didn't cause additional problems? Can you post some pictures of the board.

Congrats on finding the right screwdriver. We've been waiting for you to return

 

[whiteoutage]

No corrosion on bats but I just sold it on ebay for $15 as a "fixer upper" - would never have used it anyway. Glad to know there are still EE pros in here. You all have helped me repair stuff in the past. Forgot about ya, but will not again. Deeply gracious -thank you.