+15V supply shorted

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johntimber
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Joined: Fri 01 Jun 2018, 17:50

+15V supply shorted

Post by johntimber » Wed 06 Jun 2018, 09:00

Hi,

I have a power supply which generates a +/- 15V rail. The -15V is fine, while the +15V measures around 50mV. The 7815 gets very hot.
I suspect it's a short Unfortunately, the PSU is on a fairly large board, and I can't disconnect it from the rest of the board.
I've tried my calibrated finger all over the board, but the only thing which I've found that is hot is the regulator.
There is a 10uF tantalum (through hole, dipped epoxy style) on the output of the regulator.
So, the question: I know that these tantalums have a habit of failing short circuit. However, I'd expect it would fail more spectacularly (it looks fine). Does anyone have experience of a tantalum failing short circuit and pulling down a supply rail without appearing damaged?

Please help.

I didn't find the right solution from the Internet.

References:-
https://www.electronicspoint.com/thread ... ed.288473/
Motion graphics animation service

Thanks!

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DAUDET78
Posts: 267
Joined: Tue 16 Oct 2007, 00:30
Location: Yvelines

Re: +15V supply shorted

Post by DAUDET78 » Tue 12 Jun 2018, 22:19

Et en Français, ça donne quoi ?

arno
PMI
Posts: 717
Joined: Wed 23 Jun 2004, 21:51
Location: Un peu partout...

Re: +15V supply shorted

Post by arno » Tue 12 Jun 2018, 22:53

En français, ça donne que c'est un nouveau type de spam (plutôt malin je dois dire).

Ils copient des questions venant d'un forum d'un type proche (mais là en anglais on le lève direct...), et mettent 2 liens. Le premier est un vrai lien, qui pointe sur la question originale.

Celui qui aura vérifié ce premier lien n'aura alors pas forcement le réflexe de vérifier le second, qui est celui que le spammeur souhaite que l'on clique.

Ce sujet est le premier que j'ai vu de ce type sur ce forum, et de nouveaux sont apparus aujourd'hui. Les modo doivent être en vacances en ce moment car il n'a pas encore été supprimé.

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DAUDET78
Posts: 267
Joined: Tue 16 Oct 2007, 00:30
Location: Yvelines

Re: +15V supply shorted

Post by DAUDET78 » Wed 13 Jun 2018, 08:59

Effectivement, il a ouvert 5 discussions en patois AngloSaxon du même style

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