By: Tony
Nice video, sometimes the fun is just in hunting down the problem. Could the short be in one of the big white connectors for the memory expansion boards?
View ArticleBy: David
Did you consider trying the TTI current prober? I’ve had some luck with it for this kind of thing, especially when you can put 11 amps through the short, should a piece of piss to trace
View ArticleBy: Ray
Dave’s comment about a thermal imaging camera being useful caused me to make a mental connection. On the Hack A Day blog there was a post on Dec. 15th titled “A thermal imaging camera for your phone.”...
View ArticleBy: Alan
Could it be a faulty PSU ? Not giving enogh current, since nothing blew up, when you connected external PSU ?
View ArticleBy: Alex
Hello Dave, would also think it could be the power supply (given that the information of supplying 6 A is possibly not correct) it is not a real short given that quite some current can be normal on a...
View ArticleBy: Miad
Try giving the 11 amps with the memory cards and the processor board mounted. Also is it possible that the 3.3v plane is shorted somewhere in the board? Maybe it could be visible by placing the board...
View ArticleBy: Alan
also, rememember that the initial 11,4 A never increased, but decreased to 10,something in a while ?
View ArticleBy: Rachie
There appears to be a cracked relay case at 29:19. It seems unlikely a relay could short out like this, but it looks quite suspicious.
View ArticleBy: Alexandre Jasmin
Would it make sense to power the thing up by supplying the 3.3v rail from your high current source and try to guess what component failed by using the scope?
View ArticleBy: EEVblog
There ma be something wrong with the supply, and it needs checking. But if so, that’s a different issue. A normal 3.3V system rail should not measure 0.1ohms both ways on a multimeter. I smell a rat.
View ArticleBy: Phil Hobbs
3.3V/11A is 0.3 ohms, so if that’s accurate, the leads are also about 0.15 ohms, which seems a bit high. However, if you leave the bench supply connected you can trace tens millivolts instead of...
View ArticleBy: Alex
Hello Dave, yes thinking twice it is still a bit high current for working condition (so yes could be that only your lab supply was able to maintain driving current thru the working chips and the...
View ArticleBy: huh
I see some power 3 terminal devices on that board. Could one of them be a power mosfet? They’re known for often becoming a short when they fail.
View ArticleBy: swedeham
Hi Dave Why not try using a tone signal like a 1Khz signal connected at the 3.3 volt socket and then you trace it with a low power amp ie a pair of active PC speakers and use the 3.5mm plug as a...
View ArticleBy: f4eru
Easier : put the 10 amp Probe around the voltage with the multimeter exactly like you did with resistance => you should find quicker wich cap has the lowest voltage
View ArticleBy: Worf
I think Dave jinxed it at the beginning when he said it was a live debugging and if you’ve come to the end and it’s still not fixed…
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