magical smoke, alias what happens applying high voltage to output pin X_X

Community Bar Sport
1

so, have money, want deskside anything,
winter is coming, need heaters
good motivations to pick up a ton 90s workstation
which eats 1Kwatt just to make me to play doom1 :smiley: :smiley: :smiley:

(does it make sense?)

the machine makes more noise than a helicopter,
but it comes with a lot of circuits and pcb, and more lights
than on the christmass tree

too hApPy (sure, it makes sense)

but ... suddenly it stopped - what-the-frog ?!? -
after 2 days of inspection ...
... I found out that a chip on the main pcb had gone

so, in the attempt to repair, I got a Microchip PIC
which has an open drain output pin (MFP)
with no pull-up resistor.

oh, was too tired.... and ....
... I applied the PIC's programming voltage (VPP=8-12V)
but on the wrong pin X______X

what happened next?

My room in london was much foggier
than it had been in the days of Dickens

well, modern chips come with internal diodes for ESD protection ...
... but they aren't likely to be able to dissipate the power
generated during the programming time,
so it might work for a short time before the diodes die
the pin gets probably tied to Vcc,
and magical smoke comes like fog in town

2

:slight_smile:

3

But if you had the doors closed, you should have been able to capture the smoke. Now it is just a matter of putting it back where it came from.

Weedpharma

4

Least its not the magic fluff from an electrolytic cap...That stuff is a PITA to get back in the can...

Early experiments with a 9 volt battery just fer sh1ts and giggles and much safer than my first ever encounter with electrickery and a morse key i found at about 8 years old...Add wire, add 13 amp 240v mains plug. plug in, press key...WTF its gone dark in here apart from that very bright spark under my finger a second ago..hmm better hide this sh1t before mom and dad get home..

5

my first attempt of capturing the magical smoke into a glass jar has miserably failed
I can't put it back where it came from but the door is closed
I am not smoking some grass and the machine still makes some smoke