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<div>Dear Keith, Chris, Stefan, Hendrik-Jan and everyone else!<br></div><div><br></div><div>I've been very busy lately and didn't find the time to reply to your answers so far. Thank you for your help with analyzing my problem and suggesting possible solutions!<br></div><div><br></div><div>So, now at least I'm sure it has nothing to do with the GPU, and that it's a problem of the backlight.<br></div><div><br></div><div>I love Keith's suggestion to "hack" the screen with a LED backlight, but honestly right now, I can't imagine when I would have the free time for such a project. If I found one, my preferred option would be to replace the screen as a whole. But I didn't find a 14.1" 4 by 3 screen yet (or a whole T61 of that size where maybe something else is broken), so I'll have to to exchange the backlight separately.<br></div><div><br></div><div>I found one which I hope will fit:<br></div><div><a href="https://www.ebay.de/itm/233002573330?hash=item3640091e12:g:~0wAAOSw8PJb6T0E">https://www.ebay.de/itm/233002573330?hash=item3640091e12:g:~0wAAOSw8PJb6T0E</a><br></div><div><br></div><div>Thanks again for your answers! I really appreciate this list and the effort people put into helping each other out!<br></div><div><br></div><div>All the best,<br></div><div>Tom</div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div>29. Apr. 2021, 06:56 von keithl@kl-ic.com:<br></div><blockquote class="tutanota_quote" style="border-left: 1px solid #93A3B8; padding-left: 10px; margin-left: 5px;"><div>On Wed, Apr 28, 2021 at 11:20:14AM +0200, Hendrik-Jan Heins wrote:<br></div><blockquote><div>Apperently in these it is related to broken capacitors in the power<br></div><div>supply for the backlight.<br></div></blockquote><div><br></div><div>On Tue, 27 Apr 2021 21:01:32 +0200 (CEST) tomtom@tutanota.com wrote:<br></div><blockquote><div>with turned up brightness. Also, sometimes areas that should for<br></div><div>example be white turn a bit pinkish or even orange, mostly just for a<br></div></blockquote><div><br></div><div>I sent a more extensive writeup and suggestions to tomtom,<br></div><div>but the<br></div><div>"areas turn pinkish or even orange"<br></div><div>is the Big Clue - that means the backlight tubes are<br></div><div>producing colored rather than white light,<br></div><div><br></div><div>The pixel array is probably not responsible, and the power<br></div><div>supply can't change the /color/ of the light.<br></div><div><br></div><div>My wild guess is that tomtom's backlight is a fluorescent<br></div><div>lamp (or lamps top and bottom?), resembling the ancient<br></div><div>tube lamps over my office desk. However, unlike those big<br></div><div>overhead lamps, the volume of the spagetti-thin backlight<br></div><div>tubes is tiny, and the "end seal to volume ratio" of<br></div><div>backlight tube is enormous.<br></div><div><br></div><div>The mechanical stresses on the backlight ends are much<br></div><div>higher --- imagine shaking your office (scaled) the way<br></div><div>you shake your laptop and screen.<br></div><div><br></div><div>So in time, I would expect those backlight end seals to<br></div><div>leak a wee bit of air into a much "wee-er" backlight tube<br></div><div>internal volume. That will add the light emission lines<br></div><div>of oxygen and nitrogen (yellow and red?) to the mercury<br></div><div>vapor UV emission lines (which excites the phosphor).<br></div><div><br></div><div>The extra emission will also increase the current draw<br></div><div>of the backlight tube (it is discharging both mercury<br></div><div>atoms and the air atoms), electrically stressing the<br></div><div>inverter that drives it. So that will go soon as well.<br></div><div><br></div><div>That is a very elaborate wild guess. <br></div><div><br></div><div>Bottom line - replace the tubes, maybe the inverters too.<br></div><div><br></div><div>I suggested tomtom look for an archive of Xiphont's LED<br></div><div>replacement kit from many years past. tomtom (or one of<br></div><div>you) should consider spearheading an effort to make some<br></div><div>replacement LED strips and sell them (with instructions<br></div><div>to the rest of us. More brightness, more efficiency, no<br></div><div>leaky glass tube, no high voltage inverter.<br></div><div><br></div><div>I'd gladly buy a dozen kits at semi-reasonable price; $200?<br></div><div><br></div><div>I hope to keep using my 4x3 T60s and X61s for a few more<br></div><div>decades, replacing ancient components (including the<br></div><div>motherboard? The batteries and connectors?) with new<br></div><div>tech as it becomes available. <br></div><div><br></div><div>A future of chicklet-key runt-screen throwaways and<br></div><div>electronic toxic waste may be content-consumer utopia<br></div><div>for some, but it is my idea of hell.<br></div><div><br></div><div>Keith<br></div><div><br></div><div>P.S. As my office fluorescent tubes fail, I replace those<br></div><div>with LED tubes as well. Three times the out-of-pocket<br></div><div>cost, but I expect the LED tubes to last three times<br></div><div>longer, and not generate toxic waste at end-of-life. Also,<br></div><div>fewer toxic consequences when the next Cascadia Subduction<br></div><div>Zone earthquake happens (very seldom, but guesstimated<br></div><div>Richter 9.5). 40 fluorescent tubes breaking and spilling<br></div><div>their mercury will turn my damaged office into a superfund<br></div><div>site.<br></div><div><br></div><div>-- <br></div><div>Keith Lofstrom keithl@keithl.com<br></div><div>-- <br></div><div>The linux-thinkpad mailing list home page is at:<br></div><div>http://mailman.linux-thinkpad.org/mailman/listinfo/linux-thinkpad<br></div></blockquote><div><br></div> </body>
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