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So here's the situation. I have an old TI-84+ calculator that will not turn on, no matter what I do. Specifically, I've tried:

- Replacing the batteries, several times
- Sticking a paper clip / pencil lead in that little reset slot
- Adjusting the brightness, just in case

Unfortunately, there are a number of old TI-BASIC programs on there that I would really like to recover. That calculator gave me my first exposure to writing software, and those little programs meant a lot to me. I have to believe there is a way to dig them out. If anyone has any other ideas for getting the calc to turn I'd love to hear them, but I'm pretty certain it's bricked.

Anyway, here is what I know:

- TI calcs don't have a hard drive, but they have Flash ROM, and somewhere in there my programs must still reside.
- I have a TI Graph Link Silver cable and TI Connect installed on my Windows 10 computer, but those won't do me much good if the calc won't even turn on.
- This site has the awesome jsTIfied emulator, but I don't have a ROM image for my calc, and I won't be able to get one now that it's dead.
- I have never exposed the circuit board of the calc before. I built my own gaming computer and understand hardware well enough, but I have no idea what the ROM chip looks like, or what cables would be needed to connect to it, or if that's even possible.

Sorry if questions like this have already been asked on this forum; I found all the topics/posts kind of daunting and didn't really know where to start, so I figured I'd just start a new topic. Any help on this sentimental matter will be much appreciated!

On a related note, what's the calc that everybody recommends these days, for a replacement? Those new color screen ones look pretty cool.
You may want to try determining if there is a) anything stuck inside the circular link port; b) taking the calculator apart and checking for stuck keys, and c) checking for internal battery leakage. These usually tend to be the main causes of a calculator not turning on; and usually tend to fix things. Otherwise you can always try connecting the calc to determine if it is just an LCD failure and not a total failure. Although it is not impossible to extract information from the flash chip (a minimal microprocessor wired up to it could potentially do it), I would recommend against this.

Ideally I would look into the TI84+CE otherwise, it offers a bunch of programming capabilities and is quite nice to use.

Best of luck! Smile
MateoConLechuga wrote:
Although it is not impossible to extract information from the flash chip (a minimal microprocessor wired up to it could potentially do it), I would recommend against this.
It wouldn't be a first resort, but this is probably easier than you expect. The 83+ series has always used 48-TSOP NOR flash, which is standard enough that tools for reading and writing them are fairly common.

Noninvasive "clip" adapters for TSOP flash seem pretty easy to find, since they're used for hacking game consoles. The tricky part might be powering the memory without also bringing up the calculator's CPU; I don't know how they work on game consoles.

You could presumably also remove the chip and put it right into a socketed programmer (also pretty common and inexpensive), but you'd run the risk of damaging the chip beyond recovery in removing it from the calculator.
Excellent answers, thank you! So when it comes to opening the calc up, are there any important gotchas? Especially if all I'm doing is looking for stuck keys, are there things I should avoid touching, screws I shouldn't unscrew? Ive seen images of what looks like foil inside the case, which I assume is like a Faraday cage. Can that be removed safely? And how would I recognize/fix a stuck key?
It's a pretty forgiving design; remove the batteries (including the backup coin cell because the screw on that compartment will prevent you from opening the case) and unscrew everything, then pry the halves of the case apart.

I don't recall if there are more screws holding the board in place, but they're safe to remove if present. Then you can just take the board out to get at the keypad underlay and remove the keys themselves. It should be pretty clear if anything is stuck in there.

Just exercise basic caution around the hardware when you take it apart and you'll be fine- there's nothing particularly fragile in there.
  
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