Backup magic smoke?

Question

Ok, I messed up with my latest board and got the pinouts for the 3.3v LDO regulator wrong. I put +5 on the GND pin, grounded the Vout pin, and tied Vin to the load. (yes, the pinout was rotated).

Sure enough, when I put +5 on it, I let the magic smoke out.

So, I desoldered it and rotated the part 120 degrees just to see if I could solder it on that way. I figured the regulator was dead, but decided to check anyway.

Sure enough, when I put +5 on it, I let more magic smoke out.

Then it started working correctly!

So, two questions come to mind:

Can I trust it? It's only a 63 cent regulator, but S&H is 10x that, I'd rather avoid it, and I don't have any other parts orders pending.

Which smoke did I let out, if the part is now working correctly?

The part is a SOT-23 Microchip MCP1700T-3302E/TT, if it matters.

martin griffith · Accepted Answer

Magic smoke is a bit like noise,

white noise/smoke pink noise/smoke red noise/smoke etc but all devices are continunally emitting smoke which is the equivalent of black noise, "equal absence of energy / rt Hz"

martin

DJ Delorie · Answer

Is that the funny "on" smell we all know and love? ;-)

Also, my office definitely smells like I've accomplished something today. I hot plate reflowed eight SOJs, a SOP and a TSOP, a 0.5mm pitch TQFP, and a bunch of 0603s. Went very well, until the smoke thing.

martin griffith · Answer

Hmm, Office, so what do you do in the workshop?martin

PeteS · Answer

That's obviously for the paperwork, silly. Let's just not ask what type of paper, ok?;)CheersPeteS

martin griffith · Answer

Lead free, but then it wont sink, will it?martin

DJ Delorie · Answer

Woodworking.My "office" has software development on one side, and hardwaredevelopment on the other side.  It's just a room in my house so I cando what I want with it, mostly.

Backup magic smoke?

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