EEVblog Electronics Community Forum
Electronics => Repair => Topic started by: Fraser on July 03, 2021, 11:40:43 pm
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For those who work on moden miniaturised high density electronics, or design such, the use of thermal imaging equipment is becoming more commonplace. I have used such technology for years and have been impressed to see the likes of Alex at NorthridgeFIX using it to detect issues with computers that he is repairing. I have created two threads in the Thermal Imaging sub forum that may be of interest to those who repair modern electronics as thermal imaging equipment is becomeing more affordable every year.
If interested in this topic, take a look here.......
https://www.eevblog.com/forum/thermal-imaging/use-of-a-thermal-camera-for-pcba-thermal-profiling-and-repair/ (https://www.eevblog.com/forum/thermal-imaging/use-of-a-thermal-camera-for-pcba-thermal-profiling-and-repair/)
https://www.eevblog.com/forum/thermal-imaging/review-dianyang-technology-ca10-circuit-board-thermal-analyzer-repair-rd/ (https://www.eevblog.com/forum/thermal-imaging/review-dianyang-technology-ca10-circuit-board-thermal-analyzer-repair-rd/)
One of Alex's videos showing the use of a thermal camera for repairing a HP Spectre laptop ......
https://www.youtube.com/watch?v=fcB2ZKeuPBc&t=1s (https://www.youtube.com/watch?v=fcB2ZKeuPBc&t=1s)
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I would have replaced the charred resistor as well. Yes, I implemented this technique at work. I bought a Flir One Pro and a refurbished IPad with a lightning cable and created a “database” of normal temperatures for a variety of boards. For some boards, we reduced the troubleshooting times to nothing. For others, not so much. You need a resistance that dissipate heat. A dead short doesn’t heat up.
Anyway, OT, my daughter has a Spectre for about 5 years, probably one of the best laptops out there. Features, speed , battery life, she loved it. The battery life started going down significantly lately but otherwise, a great laptop.
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A short circuit may be investigated using low voltage injection with sensible current limiting on the current source. The actual PCB traces leading to the short will emit enough thermal energy to be visible on a decent thermal camera and a short within a component normally leads to heat emission from that failed component. The problem with current injection is that some people get carried away and use too high a voltage or current setting that causes more harm than good :(
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When I used to work for a living, one of my many hats was lighting maintenance; many hundreds of flourescent fittings, parallel wired onto power lines.
When one developed a shorted turn ballast transformer, the breaker would trip taking out a bank of lighting.
I used to find the culprit by opening the middle fitting, and measuring which direction the short short was; following the short route and dividing each run in two - it was always on the last run.
Then I bought a Fluke thermal imager. Just walk down the line looking at the temperature; every fault found in minutes, instead of up to two hours.
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Seeing in the thermal domain can be a real ‘eye opener’ :-+
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I use one once in awhile. Mines not the best but its usually good enough to get an idea of whats going on.
https://www.youtube.com/watch?v=yh6ZSDrrOXQ&t=1s (https://www.youtube.com/watch?v=yh6ZSDrrOXQ&t=1s)
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I bought an HT-18 (220x160) thermal camera off Banggood about a year ago and it's proved useful for tracking down various faults.
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I bought a second hand Seek for Android a few years ago, it's already paid for itself in time saving.