Having dealt with communications gear, when things go broken, things change electrically, and thus thermally. Having a device which has been thermally signatured can allow for quick fault localization, not having to probe in possible locations.
A thermal camera would take a signature of a device within its functional operating condition, as well as signatures for various settings within the device (AM, FM, CW, etc.)
Being able to see which components heat up and which components do not can allow you to see which signals are making it through your device, where they stop, and which settings correctly adjust signal properties/destinations. Allowing you to troubleshoot high voltage/high temperature devices without reaching your hands inside will make it a safer troubleshooting experience as well.
This system would be useful for critical systems such as cellular communications towers, ship-board communications systems, and space operations, where time is definitely critical.-- twitch, Dec 25 2012 For Example http://www.flir.com...graphy/americas/us/Just look at some of the uses shown in the ads on this page. [DIYMatt, Dec 25 2012] This is pretty widely used already. Most of the advertisements for thermal cameras show them being used for diagnosing home heating and cooling problems and sometimes mapping heat sources in computers.-- DIYMatt, Dec 25 2012 If not widely known to exist, it should be. Sometimes it's very easy - just look for the scorched place on the circuit board.-- csea, Dec 25 2012 I was musing about the difficulty with looking at a card 'end on', so to speak, when I thought: if the card was cunningly painted with different thermochromic paint in different places so that at running temperature the whole thing showed the same colour, then it would be possible to see an abnormality by eye...by mirror as well.-- Ling, Dec 25 2012 Of course, the magic would be using a trainable paint, so you simply said 'at this temperature: be white!' or whatever.-- Ling, Dec 25 2012 When transistors fail, well, at least for me, they rarely blow up. This would allow me to see which ones are cold, which should be hot. This is not just FLIR, it also incorporates a database of "normal" thermal signatures, which can easily be cross- referenced.-- twitch, Dec 26 2012 What [DIYMatt] said.
The problem with trying to record 'signatures' of devices is that that is going to vary a lot under different load conditions, e.g the output stages of an audio amp. And what if devices share a heatsink?-- 8th of 7, Dec 26 2012 For most devices it would be possible to run a test program that would set up a steady thermal state (or at most a couple of alternating ones as some things cycled on and off). It wouldn't be perfect, as no two components are exactly the same, but it would give an indicator under many cases.
That being said, the difference between a circuit that is normally idle, and one that is burned out open would be largely undetectable.-- MechE, Dec 26 2012 I'm just glad to see that people are still interested in repairing things at the component level. I was under the sad impression that "repair" these days just meant replacing the whole board, if not the entire item.-- MaxwellBuchanan, Dec 26 2012 well when dealing with mil spec, we replace down to the component level. And what [8th of 7] said about loading, take different images when in different settings. Allowing you to see what turns on and doesn't, according to the setting, will give you much to go on.-- twitch, Dec 27 2012 random, halfbakery