Hi guys, I've been reading around these forums for a bit, and I noticed that a lot of TI-83's seem to be affected by lcd ribbon failures after some years.

Are TI-84's safe from this problem, specifically TI-84+SE? How often do they suffer from these ribbon failures? Are they easy to repair if they do happen?

The ti-84 plus SE does not have a ribbon cable, therefore, they do not suffer from such failures. Here is an image of the display driver which is soldered directly on the board.



This makes LCD related issues on the ti-84s far less common. There are however other screen issues that can occur, the most common one being some pressure damage, which causes black smudges like this:



EDIT: To answer your second question, no, ribbon cable issues are not easy to fix. There have been successful attempts in the past, which involved removing the ribbon cable and soldering each pin of the lcd to the board with some gauge 40 wire (which requires a lot of skill because gauge 40 is really small, and the pins are really close to each other), but even these successful attempts have been known to not hold up over time. IIRC, there was also someone who tried using a solder pen to redraw the weak connection on the cable, which AFAIK, did not work.

What about reflow soldering? (e.g. put it in your oven at ~385F for ~10 minutes, ???, profit)

That won't help if the cable itself is what is messed up

Interesting. Do you know if the TI-89 Titanium is also directly soldered with no ribbon?

The 89T and 84+ have very similar hardware design; yes, it's the same way though the 89 has two LCD drivers (independent ones for rows and columns, apparently) rather than the single one used in the 83+ series.

You can see just how similar the TI-89 Titanium LCD connection is in an old topic where one of our members disassembled and backlit a TI-89 Titanium.