Timeline for LED intermittently fails but works when voltmeter applied
Current License: CC BY-SA 4.0
6 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| May 30, 2019 at 14:46 | comment | added | Brick | I eventually took the whole project apart, cut this LED out, replaced it with a new one, and for good measure retouched all solder joints along the way. It's been working perfectly since reassembled. I kept the problem LED and may experiment on it at some point - if I ever get unlimited free time! Will consider continuously monitoring voltage if I come around to that. | |
| Apr 15, 2019 at 12:22 | comment | added | Spehro 'speff' Pefhany | Did you understand my suggestion to ‘instrument’ it by adding leads to the DMM so the voltage is continuously monitored? | |
| Apr 15, 2019 at 12:19 | comment | added | Brick | I see, that was not clear. I did the twist-and-tug test before resoldering and repeated it after resoldering. I did the resolder in this case even though it seemed that everything was secure because I was running out of ideas. | |
| Apr 14, 2019 at 22:47 | comment | added | Spehro 'speff' Pefhany | You've already resoldered it. You can try soldering leads to the LED and monitoring the voltage. If you ever observe it exceeding the normal Vf of a few volts (tops) then the problem is inside the LED. Otherwise there's a small chance it's something weird with the presence of the probe. | |
| Apr 14, 2019 at 22:14 | comment | added | Brick | As I tried to note originally, I can wiggle and twist the leads at the LED and the wires anywhere else that I've tried. I cannot make it fail when it is working. That seems to eliminate your answer as I understand it and according to your own second paragraph. | |
| Apr 14, 2019 at 15:17 | history | answered | Spehro 'speff' Pefhany | CC BY-SA 4.0 |