Ti82 Lcd In A Ti83silver

[fninjap90]

My TI83S's screen isn't working really well, so I want to install a new one. I called TI and they said that they don't sell the screen individually, so I guess I'll need to just get an inferior calculator and pull out the screen.

I see that both the TI82's and the TI83S's screens are 64x96 pixels. If I carefully remove the screen and its ribbon tape from my TI83S, can I solder the the screen and its ribbon tape of the TI82 to the tabs for the ribbon tape on the TI83S?

Would it be a direct bolt on replacement?

Thanks.

[DigiTan]

Hey, what's this I hear about the TI-82 being an inferior calc?

Oh Well. To answer your question, it's possible, but re-soldering the plasic ribbon is a very tall order. The plastic flex connector is particularly intolerent of heat, and most soldering jobs are done using a technique called hot bar soldering. That's usually done through an automated process (aka "Reflow" soldering) where the temperature is computer-controlled for precision. Manual jobs are possible, but on with specialized equipment.

Also there's the problem of the display driver chip (which is Toshiba #TGA43 for TI82 and 85). You'd also have to make sure your current driver is 100% compatible with the new sceen, or else you could see some serious display problems.

Well, to sum it up. LCD mods are possible, and they've been done before. But it's a very difficult process. Some calc sites might have more information them though.

[Dwedit]

From a software perspective, the LCD screens respond to the same command sets on the same z80 ports, but that's some software thing.

[fninjap90]

Hmm so the driver won't be compatible?

Do you know where I can just get TI83 screen by itself? The driver on my calculator is the thing that's broken. There is a slight rip in it which is causing the bottom 1/4 of the screen to not display.

[DigiTan]

It could be compatible in software terms, but since each calc model has a unique chipset, you'll want to at least check to see if the driver chip is the same. Otherwise, strange things start to happen.

I'd probably concentrait on replacing that cable, and since it's already torn I say you've got little to lose. The type you're looking for is called a fine pitch flex cable, and its generally only used in with these dot-matrix displays. Start by checking with tech forums like electro-tech-online to see if you can contact anyone who specilizes in this equipment. They might be able to provide more details.

Also, if your interested, 8052.com did a similar project with a 106x56 pixel display using another type of flex cable. So it kind of proves this kind of thing can be done.

[fninjap90]

Ok, well the current busted driver in my 83se is a Toshiba T6K04. Does every calculator in the 83 series have the same driver? If they do, I can just get a LCD/driver assembly from a normal 83, stick it in my 83se, and it would work perfectly, right?

Also, to the bottom and right of the driver, imprinted on the big circuit board behind the LCD, is the type

<CT> 003V0 0120
94V-0
9TA0867LB-30C 1/A

Do all 83 screens have that?

[DarkerLine]

I think that the 83 and 83+SE have essentially the same screen.

[AlienCC]

Just to clear up some confusion that is being stated.

A Driver, is a piece of software that allows the operating system, and other software to communicate with the hardware device it is written for. Drivers are usually either written in a modular format which can be loaded easily into the OS running it.

A Ribbon, is a piece of hardware, a thin cable which connects two other pieces of hardware together, in this case an LCD, and the PCB (Circuit Board).

In theory You should be able to use the TI-82, 83, or 83SE screen as a replacement, ribbon cable included. Careful with those ribbons they weren't made to be bent, and doing so too much will damage the cable.

--AlienCC

[fninjap90]

Okay, here is my calculator.






When I was drilling the holes in the front, I was being stupid and had the screen in the same place. I learned my lesson after the drill went into "B"



That's the driver right? Well it's the part that's broken.

Now I need a new "A". Will a TI82 "A" directly replace my "A"?

[DigiTan]

That's the gist of it. It might be a different case if all the traces are still intact and only the chip were destroyed. Then it's just a matter of replacing the chip, which can actually be done by hand. From the looks of the calc mod, I'm guessing you're no stranger to soldering, so a repair might be possible. But if the traces or footprinting is damaged, I'd say it might be time for a new calc.

[fninjap90]

I'm pretty confident I can solder the 17-lead base of another ribbon tape to the leads of my main chip.

But what do you mean by traces and footprinting being damaged? Like my soldering iron melting together the 17-brass areas of the main chip? Sorry but I'm pretty newb in electronics. I'm still in high school.

You still haven't answered my question though. Will I be able to take the "A" from a TI82 and directly replace the "A" from my 83se?

[aforsy]

shouldn't this be in the calc mods forum?

BTW, your calc case looks awesome!

[leofox]

yeah, why is this in open topic?

[fninjap90]

Hmm, I guess so. But this forum seems like it's more popular than the mods forum. I guess the mods can move it. Or I can just start another thread there.

[DigiTan]

It may be possible to replace section B, but you can avoid a lot of trouble by replacing only the damaged chip if that's an option (hard to tell from the image). I'm not familar with TI-83+ LCDs so it's hard to tell if section B is seperate from the mainboard or not. From what I can tell from the images, it looks like that section is seperate and its being connected to the mainboard though some kind of ribbon connecter with some...44 conductors or so. In order for this to work, your new section B would have to have identical properties with the old one (anotherwords, it must be 'pin compatible'). Most likely, that new section would have to come from another TI-83+ SE, since TI uses a different chipset in every calc model.

Since no one's published a circuit diagram of a TI-82/83+ I can't be absolutely certain.

[fninjap90]

Digitan, perhaps I haven't gotten my point across clearly.

I'm under the impression that you think that I want to replace only "B".

I have no intentions of getting a new Toshiba T6K04 ( and installing it myself. I do not have the ability and soldering skills to do the 44 small tacks of replacing just the driver.

What I want to do is get a new "A", which consists of the circuit board, LCD screen, and T6K04 from a cheaper calculator, and replace my current "A" with the new "A".

[DigiTan]

In either case, if the part you're planning to replace is not pin compatible with what you're removing, the repair won't do any good..."A," "B," or otherwise. There is about 0 documetation on these parts, and since TI's chipset changes with each model, using TI-82 parts is probably asking for trouble. The image below shows that they at least look similar, but it's impossible to judge it without schematics from both models. My advice: (1) Compare the ribbon interfaces of the TI-83+ SE and the TI-82, to see if at least the number of connectors match. (2) try replacing the LCD network ("section A") using the hot bar method. (3) Measure the resistance across the power leads (the 2 widest conductors on the ribbon) to make sure you have a non-zero resistance (to avoid a short). (4) Apply power and monitor the screen for at least 60 seconds to make sure the display is not being overpowered.

[DarkerLine]

If there were some lcd issues with the new "Blue" 83+, there's gotta be issues with the 82.

[fninjap90]

Alright, I won't try the swap with a TI82.

But if I try it with a TI83/TI83+/TI83+SE, would it work perfectly? Do all the TI83's have the exact same LCD and driver?

[DarkerLine]

Except for the new ones, prolly.