Screen went blank replaced AAA batteries starts up

Remove all four AAA batteries. Press and hold the ON key for ten seconds. Replace the batteries. Turn the calculator on (you may have to adjust the screen contrast again).

If this doesn't do it, please add a comment to this post and we'll go on from there.

TI calculators have an annoying habit of dimming the screen when the batteries are changed so that it appears as if the calculator isn't turning on. Turn the calculator on (or at least press the ON key). Press and release the 2ND key. Press and hold the Up-arrow key for a few seconds and see whether the screen becomes legible.

If that doesn't do it, remove all four AAA batteries. Press and hold the ON key for ten seconds. Replace the batteries. The calculator should come on (you may have to adjust the contrast as described earlier).

it seems it have an internal problem of contact and you must get it repair, or consider buy a new one that model is a little old.

You may need to replace the backup battery located behind a little door with a screw right above the AAA batteries. If that doesn't work you might want to try a full reset. Take all batteries out including the backup battery and leave them out for a few hours before reassembling. Hope this helps.

http://www.associatedcontent.com/video/265/how_to_reset_a_texas_instruments_ti89.html

Remove one of the AAA batteries.

Press and hold CLEAR while reinstalling the AAA battery.

Continue holding CLEAR button and press ON.

Release buttons and press CLEAR again.

Calculator should be normal mode now.

Has it been dropped recently? The screen may have cracked from impact. Press the Reset button on the back using a ball point pen.

i found this somewhere else on this website
and it worked for my broken ti-83plus which had same odd startup symptoms.

Remove one of the AAA batteries.
Press and hold CLEAR while reinstalling the AAA battery.
Continue holding CLEAR button and press ON.
Release buttons and press CLEAR again.
Calculator should be normal mode now. ;0)

Try adjusting the brightness by pressing 2nd key or witchever name is on yours for the Alt key + the up or down arow key(as you see fitted)

Try replacing both the AAA batteries and the back-up batteries. This should probably fix the problem.

Remove one of the AAA batteries. Press and hold CLEAR while reinstalling the AAA battery. Continue holding CLEAR button and press ON. Release buttons and press CLEAR again.