From: Mike Harrison
Subject: Re: cheap IR camera?
Organization: White Wing Logic
X-Newsreader: Forte Agent 1.9/32.560
Date: Wed, 25 Sep 2002 12:52:53 +0100
NNTP-Posting-Date: Wed, 25 Sep 2002 12:52:58 BST
On Thu, 19 Sep 2002 16:39:33 +0000 (UTC), Ian Stirling
>In sci.electronics.design Ian Stirling wrote:
>> In sci.electronics.design George Gonzalez wrote:
>>> Lately I've been resuscitating a pallet-load of Tek 465 and 475 scopes.
>>> Most of the rest have shorted tantalum capacitors from one of the power
>>> supplies (-8, -15, +5, +15) to ground. These are a bit difficult to find,
>>> as there are many caps sprinkled around the boards. The method I'm using
>>> now is to push a few amps into the shorted power bus with an external power
>>> supply, then feel around for warm or hot capacitors.
>> As others have said, IR cameras are expensive.
>> If you have a shorted decoupling capacitor, then if you poke around looking
>> at all the cap negatives, then the one you want will have the highest
>> positive voltage.
..but infrared thermometers are a LOT cheaper - you can get some with
laser sights, but I don't know if they are useful at such close
You might be able to get one of these and hack the optics for your
purpose - for this type of application, perhaps you could add an
acoustic output for rapid location of hotspots by scanning around..?
>Alternatively, if you stick it in the freezer, generate frost on it, then
>do the test, that could also indicate warm bits.
..and get moisture all over the board... Maybe use CO2, which
evaporates from solif to gas - a quick blast with a CO2 fire
extinguisher could be an easy way to reveal hotspots!