Fix the light guide in a laser meter

Fix the lightguide in a laser meter (Luigi Rizzo, 2025-03-02) Over time I bought a few PLEM 50 Laser Meters from LIDL/Parkside. Most of them worked flawlessy. The last unit, however, PLEM 50 D4, is problematic. I almost constantly get "Error 255" messages at almost any distance and conditions (I am apparently not alone, judging on feedback on this and similar devices). The error is related to a problem with the sensor (low signal or so) and is expected at long distances, or in bright light. But on my D4 this is happening practically always, even when previous units worked flawlessly. I opened the device and found that it uses I opened the device and found that it uses the module on the left for which there also a datasheet The brass disc on the left is some kind of led, which pulses red when it measures. The black rod above the led is some kind of lightguide passing the light towards the unit on the right that contains some kind of light sensor, and the lens used for measurement. In ... Read full article.