What happened to my OS?

[emperorwiggy]

Something is seriously wrong with my TI, and I don't have the faintest idea what.
This worries me, because I usually have a couple of guesses.
Anyways, one day about a week ago, I decided to group a Basic program and the variable A. I have never had any trouble doing so, and I have grouped hundreds of them with no trouble.
However, this time,although it should have taken about 10 seconds, it didn't stop. After 30 seconds, I noticed that the run bar was frozen. I waited 10 minutes, and then the new batteries ran out. Fortunately, I still had a fresh backup battery installed, so I switched the batteries out. When I turned my calculator on, instead of resetting the RAM, the screen was random frozen black and white pixels. The TI did not respond, other than turning off when I pulled a battery out, and turning on when I put it back in and hit on.
So, for about a week, I've been keeping the batteries out, and holding the on and/or clear buttons, and putting the batteries back in and turning it on, only to find absolutely no change. The TI cannot connect to my computer now. If anybody knows different ways to hard reset a TI 84, please tell me. I don't care if I lose everything, I just want my TI fixed.

[magicdanw]

I believe you can force the calculator to accept a new OS by holding Delete and pressing On. Then, it should tell you to send an OS, and you can do that from the computer with an OS downloaded from ti's website.

Edit: Oops, I forgot - Welcome to United TI! I hope you enjoy your stay, and don't worry - the forums don't usually look this...ancient. I expect we'll be seeing an upgrade within 24 hours

[emperorwiggy]

Wow, first try! Thank you very much - I didn't think that my OS was still functional, but, obviously, it is.

I thought I knew everything about debugging TIs. This just goes to show that I don't.

I hope I don't offend you, but was that a suggestion, or do you actually know what happened?

[magicdanw]

Your welcome, and I'm glad that it all worked out ok. Did I know exactly what was wrong? No, it could have been any of a number of things. But I did know that Del+On was a good thing to try, because I used it on a friend's calculator once that didn't respond to anything else (and also showed some weird stuff on the screen), and it got his to accept a new OS.

Anyway, glad to have helped!

[emperorwiggy]

Dang.

When I turned my TI back on, the same thing occurred. This tells me 3 things:
1. I have a new OS. That's not the problem.
2. After pulling out the batteries, I didn't have any RAM left to cause a problem.
3. Because I was grouping something, the error is probably with the flach memory.
So...
Does anyone know how to emergency reset ROM? I know it's possible because one of my peers had to do it. I feel guilty about whining about my problem and waiting for other people to fix them, so I'd be immensely grateful if someone were to tell me how to reset my TI.

[Iambian]

When you try to do the ON+DEL trick to reinstall the OS, try to tap the MODE button while doing so. If done right, it'll start a "flash test". This process will clear just about everything on the calculator (except the boot code). If the problem is with flash, the test should fail.

If it's not the Flash, then it may be the OS that you're using. I have encountered grouping problems with OS version 2.41 that seems to happen every once in a while in a very random, unreproducible way. With that problem, the group failed to ungroup properly. I don't know if your problem is related in any way, but you may want to try installing a different OS version. You can probably find a version different from the one on TI's site from one of your peer's calculators.

[emperorwiggy]

Thank you - you're right, it's the Flash.

I already suspected that the OS was fine, because I booted the 2.43 OS onto my TI, and the same error occurred.

Now that I know what's wrong, all that I need to do is to find out how to clear the Flash...

[Iambian]

The problem isn't the contents of Flash.

When a Flash test fails, it tells you that the Flash memory itself is bad. Basically, the test is to fully write the flash sector then clear it. If not all the bits in the page are cleared, it tells you that the flash memory for that sector cannot be used reliably for data storage. If the sector used resides in the temporary swap sector, this is bad. Even worse if the bad sector resides where the OS is.

If the flash test fails, the only realistic option is to replace the entire calculator.

If you're into unrealistic solutions, you can open up your calculator and attempt to replace the Flashrom chip yourself, but if you take that approach, you'd have to copy the bootcode from the old flash chip, put it into the new flash chip in the same location, then appropriately hardware-protect that sector so that it cannot (easily) be reprogrammed in-system.

...
I'm aware that you did NOT want to hear this.
If the calculator is still within warranty, I suggest you try to get it replaced by TI.

[luby]

Send an email to TI. They might send you a new one. It's happened before.

[emperorwiggy]

Huzzah!
I was screwing around with my TI, trying to find an emergency reset, and I found that doing the DEL-ON trick, and holding CLEAR instead of DEL clears the RAM, ROM, and most of the Flash (clears groups, not apps). I'd replace it if I could, but the warrenty ran out about a month ago (of course).
Now I can get on with my life, and with learning ASM. I'm sorry for basically wasting your time.

Now, if no-one needs this forum anymore...

Do I delete it, or what?

[TheStorm]

No, keep it so others with you same problem can use it to find answers instead of starting a new thread.

[Liazon]

you should probably set up an emu if you're going to learn ASM.

it'll keep the calc alive longer ^^