Login [Register]
Don't have an account? Register now to chat, post, use our tools, and much more.
On the Repair of TI-83+ LCDs
Published by KermMartian on October 3, 2010 at 11:11:37 PM CST | Discuss this article (133)

Over the past many years, there have been many, many calculators of the TI-83, TI-83+, and TI-83+SE persuasion that have suffered from the dreaded "black LCD" syndrome. You can power them on and off, you can see them and their contents via linking programs like TI-Connect, but it's impossible to see anything on the screen other than solid black. Over the years, I've been fortunate enough to acquire quite a few such calculators from sources such as colleagues and eBay, but until a few weeks ago, I assumed that the failure was in the tiny surface-mounted black square that takes the 15 pins of signal data from the calculator's CPU and turns it into 96 columns and 64 rows of data (plus contrast and power settings) for the LCD. Fortunately for me, my discoveries of the real solution started with a calculator with a garbled LCD. Indeed, it was a TI-83+ that behaved like a TI-84+ with a bad LCD delay: on the homescreen it was more or less fine, other than a few garbled characters, but launch Doors CS and it suddenly started rotating the screen by 2 bytes (for you non-ASM types, the rightmost 16 columns of pixels pushed their way over to the left side of the screen). To me that indicated some kind of skewing in the data being send to the LCD, but that wouldn't be a true failure of the LCD controller, since the homescreen was fine.

Intrigued, I pulled out my multimeter and checked the ribbon cable connecting the calculator's mainboard and its LCD module. To my great surprise, I found that a few of the connections had resistances at least one or two orders of magnitude higher than the others, even though all appeared connected. I wavered for a bit, then took the plunge. Whipping out my trusty soldering iron, I burned away the metallicized plastic trace from the offending connections, cleaned the respective mainboard and LCD PCB traces, and carefully soldered some 30awg wire into place. After a few adjustments, I turned on the calculator to discover that the LCD was behaving like the day it rolled off the assembly line!

Since then, I have fixed about five calculators in my collection displaying solid-black LCDs or garbled LCD behavior via partial or full replacement of the ribbon cable connecting the LCD PCB and main PCB. The photos below are from tonight\'s adventure, a particularly ambitious one in which I transplanted the working LCD from a calculator with a completely dead mainboard, to a mainboard that showed up on TI-Connect but refused to even display a black rectangle when power was supplied to the LCD. Here are some details of the repair, plus a gratuitous pic of the functioning calculator.

Protip: 30awg wire stripping: nail clippers! Thanks for that tip, Internet.



Permalink
2010 Articles
January 2010 January 2010 [Back to News Archives Index]

» Happy New Years from the FreeBuild crew published January 1, 2010 by elfprince13
» [Beta] SysMon Server Monitor published January 15, 2010 by KermMartian
» Bring the Calculators Back to IRC: Reviving #ti published January 21, 2010 by allynfolksjr
» SysMon v1.0 published January 25, 2010 by KermMartian
» Freebuild Linux Support published January 26, 2010 by elfprince13
» One Hundred Thousand Posts published January 31, 2010 by KermMartian

February 2010 February 2010 [Back to News Archives Index]

» TI-84+ OS v2.53 Leaked published February 7, 2010 by KermMartian
» Ultimate Calculator 3 Progress published February 8, 2010 by KermMartian

March 2010 March 2010 [Back to News Archives Index]

» Three New BASIC Programs published March 26, 2010 by KermMartian

April 2010 April 2010 [Back to News Archives Index]

» SAX "Dupe Aborted" Bug Fixed published April 9, 2010 by KermMartian
» Doors CS 7 Development Grinds Sluggishly to a Start published April 16, 2010 by KermMartian
» Promotions; Sonic Screwdriver published April 28, 2010 by KermMartian
» DCS7 Dev Continues; Long-Overdue PwdSE v2.0 published April 29, 2010 by KermMartian

May 2010 May 2010 [Back to News Archives Index]

» DCS7 Dev: TabFuncs, Folder Restore published May 3, 2010 by KermMartian
» Doors CS 6.3 Beta published May 12, 2010 by KermMartian
» BinPac8x v1.0 published May 20, 2010 by KermMartian
» Master's Thesis Completed published May 25, 2010 by KermMartian
» Master's Graduation; DCS 6.4b Coming Soon published May 27, 2010 by KermMartian
» Doors CS 6.4 Beta published May 30, 2010 by KermMartian

June 2010 June 2010 [Back to News Archives Index]

» BinPac8x v1.2 published June 1, 2010 by KermMartian
» Doors CS 6.5 Beta published June 5, 2010 by KermMartian
» SourceCoder 2.5: Updates and Features published June 11, 2010 by KermMartian
» TI-84+ Etch-a-Sketch With Real Shaking published June 12, 2010 by KermMartian
» Doors CS 6.6 Beta published June 19, 2010 by KermMartian
» Cemetech Contest #7: Doors CS published June 22, 2010 by KermMartian
» DCSB Libs Progress published June 27, 2010 by KermMartian

July 2010 July 2010 [Back to News Archives Index]

» Doors CS 6.7 Beta published July 2, 2010 by KermMartian
» Return of the mobileTunes 3 Converter Upgrades published July 6, 2010 by KermMartian
» Doors CS 6.7.6 Beta published July 21, 2010 by KermMartian
» Doors CS 6.8 Beta published July 25, 2010 by KermMartian
» Cemetech Contest #7 Deadline Fast Approaching published July 29, 2010 by KermMartian
» BinPac8x Updated to v1.3 published July 30, 2010 by KermMartian

August 2010 August 2010 [Back to News Archives Index]

» Doors CS 7 SDK Released published August 4, 2010 by KermMartian
» Tokenizer DE v1.0 Released published August 6, 2010 by KermMartian
» Presenting Document DE 7 published August 10, 2010 by KermMartian
» Doors CS 6.9 Beta published August 13, 2010 by KermMartian
» Doors CS 7.0 Release Candidate 1 published August 20, 2010 by KermMartian
» Doors CS 7.0 Released! published August 25, 2010 by KermMartian
» Contest #7: One Week to Go! published August 29, 2010 by KermMartian
» Updates: Stats, Forum, Mobile published August 31, 2010 by Alex

September 2010 September 2010 [Back to News Archives Index]

» Contest #7 Now Closed published September 5, 2010 by KermMartian
» CALCnet2.2 Demonstrates Calculator Networking published September 6, 2010 by KermMartian
» NetPong v1.0 Showcases CALCnet2.2 published September 10, 2010 by KermMartian
» New Global Moderators published September 13, 2010 by KermMartian
» Cemetech Contest #7 Results published September 14, 2010 by KermMartian
» Landmark Months; Contest Downloads; CALCnet 2.2 published September 29, 2010 by KermMartian

October 2010 October 2010 [Back to News Archives Index]

» On the Repair of TI-83+ LCDs published October 3, 2010 by KermMartian
» CALCnet2.2 Manual/Whitepaper; Site Uptime, Downtime published October 8, 2010 by KermMartian
» Upgrades and Downtime; DCS 7.1 Beta Soon published October 29, 2010 by KermMartian

November 2010 November 2010 [Back to News Archives Index]

» Doors CS 7.1 Beta 1 published November 8, 2010 by KermMartian
» mobileTunes v3.2 Released published November 10, 2010 by KermMartian
» Ramping Up to CALCnet2.2 & DCS 7.1 published November 12, 2010 by KermMartian
» Cemetech At 2^17 Posts, Active Despite Crunchtime published November 29, 2010 by KermMartian

December 2010 December 2010 [Back to News Archives Index]

» Doors CS 7.1 Beta 2 published December 5, 2010 by KermMartian
» Doors CS 7.1 Released! published December 14, 2010 by KermMartian
» Merry Christmas, Cemetech and DCS7 Updates published December 26, 2010 by KermMartian

Advertisement