Frustrated by his Aldi multimeter’s backlight turning off after just 15 seconds, [Steg Steg] took matters into his own hands. His solution? He added a manual toggle switch to control the backlight, allowing it to stay on as long as needed. He began by disassembling the multimeter—removing the outer bumper and a few screws—to access the backlight, labeled “BL.” He identified the voltage regulator outputting 2.8 V, desoldered the red wire, and extended it to install the switch.
On his first try, he successfully drilled a spot for the SPST switch. To fit the switch into the multimeter’s rubber bumper, he used a circular punch, although his second hole wasn’t as clean as the first. Despite this minor setback, the modification worked perfectly, giving him complete control over his multimeter’s backlight without the original 15-second timeout.
Canadian consumer goods testing site RTINGS has been subjecting 100 TVs to an accelerated TV longevity test, subjecting them so far to over 10,000 hours of on-time, equaling about six years of regular use in a US household. This test has shown a range of interesting issues and defects already, including for the OLED-based TVs. But the most recent issue which they covered is that of uniformity issues with edge-lit TVs. This translates to uneven backlighting including striping and very bright spots, which teardowns revealed to be due to warped reflector sheets, cracked light guides, and burned-out LEDs.
Excluding the 18 OLED TVs, which are now badly burnt in, over a quarter of the remaining TVs in the test suffer from uniformity issues. But things get interesting when contrasting between full-array local dimming (FALD), direct-lit (DL) and edge-lit (EL) LCD TVs. Of the EL types, 7 out of 11 (64%) have uniformity issues, with one having outright failed and others in the process of doing so. Among the FALD and DL types the issue rate here is 14 out of 71 (20%), which is still not ideal after a simulated 6 years of use but far less dramatic.
Cracks in the Samsung AU8000’s Light Guide Plate (Credit: RTINGS)
As part of the RTINGS longevity test, failures and issues are investigated and a teardown for analysis, and fixing, is performed when necessary. For these uniformity issues, the EL LCD teardowns revealed burned-out LEDs in the EL LED strips, with cracks in the light-guide plate (LGP) that distributes the light, as well as warped reflector sheets. The LGPs are offset slightly with plastic standoffs to not touch the very hot LEDs, but these standoffs can melt, followed by the LGP touching the hot LEDs. With the damaged LGP, obviously the LCD backlighting will be horribly uneven.
In the LG QNED80 (2022) TV, its edge lighting LEDs were measured with a thermocouple to be running at a searing 123 °C at the maximum brightness setting. As especially HDR (high-dynamic range) content requires high brightness levels, this would thus be a more common scenario in EL TVs than one might think. As for why EL LCDs still exist since they seem to require extreme heatsinking to keep the LEDs from melting straight through the LCD? RTINGS figures it’s because EL allows for LCD TVs to be thinner, allowing them to compete with OLEDs while selling at a premium compared to even FALD LCDs.
LCD televisions are a technological miracle, but if they have an annoying side it’s that some of them are a bit lacklustre when it comes to displaying black. [Mousa] has a solution, involving a small LCD and a bit of lateral thinking.
These screens work by the LCD panel being placed in front of a bright backlight, and only letting light through at bright parts of the picture. Since LCD isn’t a perfect attenuator, some of the light can make its way through, resulting in those less than perfect blacks. More recent screens replace the bright white backlight with an array of LEDs that light up with the image, but the electronics to make that happen are not exactly trivial.
The solution? Find a small LCD panel and feed it from the same HDMI source as a big panel. Then place an array of LDRs on the front of the small LCD, driving an array of white LEDs through transistor drivers to make a new responsive backlight. We’re not sure we’d go to all this trouble, but it certainly looks quite cool as you can see below the break.
Many of us misspent our youth fixing televisions. But fixing a 1970s TV is a lot different than today — the parts were big and tubes were made to be replaced. Have you torn into a big flat screen lately? It is a different world, as [The Fixologist] shows us in the video below.
The TV in question was rescued from a neighbor who was about to throw it away. If you are like us, you’ll watch the first few minutes and see it powers up, but the screen is very dark. Back light problem, right? No problem. But it turned out to be more than we thought.
Honestly, we assumed it might be the power supply, and we would have put a power supply on the LED leads to test that first. That would have been smart because taking the panel off to reveal the LEDs was very difficult! There were two bad LEDs, though, so in the end you’d have had to do it anyway.
We were disappointed that after fixing the LED, he cracked the LCD panel during the reinstallation. So, in the end, this was more of a teardown video and not a repair video. He seemed to think a lot of the tape in the unit was to thwart repairs. That could be, but we wondered if it made manufacturing the TV easier which, after all, is mostly what they care about.
Back in the days before the widespread adoption of smartphones, Palm was the market leader in PDAs. If you had one of those you’ll probably remember taking notes by writing those funky “Graffiti” characters and tapping your stylus onto, usually, a green monochrome screen. Some models even came with a battery-hungry backlight, but for the ultimate display experience you had to buy the Palm IIIc that came with a backlit full-colour display.
While revolutionary for its time, it was hampered by the technology available: the CCFL backlight took a second to start up, and even with the screen at full brightness it was rather dim by today’s standards. [TobleMiner] fixed these issues by designing a module to retrofit an LED backlight into your Palm IIIc.
The new backlight consists of a long, thin PCB designed to fit exactly where the CCFL tube sits. The PCB holds twenty-one white LEDs along with their current-limiting resistors to provide even illumination from top to bottom. A little MOSFET soldered onto the mainboard ensures the new backlight also correctly responds to the device’s “brightness” setting. [TobleMiner] recommends to remove the bulky CCFL transformer from the Palm’s mainboard to disable the corresponding circuitry and save a bit of weight.
The end result is understandably hard to capture on camera, but apparently gives the screen more vibrant colours. In any case, this might be a useful hack for anyone with a Palm IIIc with a broken backlight, though we can’t remember if that was a common issue. If you’re among those who still use original Palm devices, you might like this Palm-compatible Bluetooth keyboard. Don’t have a classic PDA? You can also run PalmOS on modern custom hardware.
The Casio F-91W is easily one of the most iconic and popular watches worldwide. But what’s cool about having the same exact thing as millions of other people? Not much, unless of course you modify it to make it your own. That’s exactly what [Gautchh] did to their beloved watch. Between permanent dark mode, stereo blue LED backlights, and a new strap, this timepiece really stands out from the crowd.
Once [Gautchh] got the watch open, the first order of business was to re-polarize the LCD with a different film so the digits are light and the background is dark. This watch ships with a single green backlight LED that’s fairly faint, so [Gautchh] upgraded it to bright blue and added a second 1206 LED in parallel on the other side of the readout. Finally, they replaced the rubber strap with something less likely to chafe.
We think dark mode looks great, though [Gautchh] says it requires a little bit of training to hold your wrist just right to make it readable. They make these mods look easy, but they likely aren’t for the faint of heart. If you want to give it a shot, there are good step-by-step instructions and several pictures to help out.
The AlphaSmart NEO and NEO2 are great little word processors for distraction-free writing anywhere you want to go, but they lack the backlight of the later Dana model. Well, [starboyk] has done what many thought impossible and added a backlight to a NEO2. Experience gained from a ton of console mods and repairs led to the question of whether the NEO2’s LCD is similar to a Game Boy’s.
[starboyk] started with a fresh NEO2 from ebay, then swapped out the reflective polarizer for a translucent polarizer and added a trio of LED backlights meant for the original Game Boy across the back of the screen. The best part is that the backlight has its own power switch and a brightness control pot. It sounds easy enough, but this mod is not for the faint of heart as it sounds like a really tight fit in the end. Apparently we only need 500 orders to get a custom backlight manufactured, but barring that does anyone know of a backlight that’s 157mm x 44mm?
You can always stick with the mod where you power the USB-A port and use a USB reading light like I did with my NEO.
