why is posting photos so slooooow is the internet melting down

got this Compaq LTE 386s/20 as a repair challenge, would be perfect to run Citadel-86

power brick appears to work, 30v on two pins

plug it in to the laptop, the light flashes and you can hear it start and shut down, oh yeah that's a short

lets get it apart

sum magic smoke let out by the battery

#retrocomputing #repair #magicsmoke

So I had - past tense - one of those cheap but incredibly useful and surprisingly capable MCU-based component testers. You know the ones - they cost about twenty bucks, can identify virtually any 2- or 3-terminal device you stick in their (usually ZIF) socket, as well as telling you things like which leads are gate/source/drain, base/collector/emitter, anode/cathode, or whatever else you might want to know about a lot of electronic components.

Absent-mindedly put an electrolytic capacitor into it tonight without discharging it. Had about 22 volts in it... hence, one ex-tester. I let the magic smoke out, without actually releasing any smoke or smell.

Oops.

#electronics #hobby #MagicSmoke #oops #ComponentTester #LCR #LCRMeter #component #transistor

@oldclumsy_nowmad

YW 😉

Indeed, connecting something labelled "NC" to ... well, anything ... will, under ideal conditions, do nothing. Under more realistic conditions you can expect misbehaviour or worse, up to and including releasing the magic smoke in a violent manner.

If the manufacturer wants you to tie unused pins to ground, or Vcc, or something else, they'll tell you explicitly in the datasheet. They definitely won't label them "NC" ... in a correct datasheet, anyways.

#MagicSmoke #KineticFunctioning

Okay Mastodon let's see if you can help.
I have this TPS560430 DC/DC buck which now has blown up twice on similar boards.

In both cases the failure occurred when plugging in to a live 24V 2A source. It appears the DC/DC has some kind of latch up and catches fire. Downstream of the buck is a TVS which is used for protecting some I/O ports, an STM32 and a few bits and pieces.

For a temporary workaround I've placed a 100R resistor between the 24V supply and the TPS560430, but I'm not sure of the cause and whether this resistor would help. It's also going to affect stability of the buck especially under load.

Anyone have an idea where I'm going wrong?

#electronics #buck #dcdc #magicsmoke

When the repair is unsuccessful and you let the magic smoke out...

#aiart #scifi #fanart #photography #alien #cyberpunk #fail #hitech #mecha #photorealistic #robot #spiderbot #unlucky #magicsmoke

Wir haben einen neuen Sticker "Powered by Magic Smoke" und das tolle: Kostenlos für euch! Gleich zuschlagen, nur so lange der Vorrat reicht ;)

https://shop.blinkyparts.com/de/Blinkyparts-Logo-Sticker-10er-Pack-Powered-by-Magic-Smoke/blink23168

#PoweredByMagicSmoke #LötenVerbindet #solderingconnects #magicSmoke

No, I didn't solder a very clearly marked polarized electrolytic capacitor backwards across the power rails of my project board tonight, causing it to smell funny, emit a loud POP, and spit its guts across the room.

Not that you can prove, anyway.

#electronics #MagicSmoke #electrolytic #polarized #soldering #oops

Measuring the characteristics of some cheap J113 / 2SJ113 n-channel JFETs I bought, so I can match them / divvy them into bins.

Put #15 of 20 into the JFET test circuit, and the power supply's current limiter kicks in ... whoops. Did I have it turned around so I swapped the terminals? Nope...

Take a peek at it. Slightly different marking. Still "J113", but the factory/date code is different. Put it in the component tester... it's a PNP BJT transistor, not a JFET at all, and with a pinout completely unsuitable for the JFET test circuit. If it had been in for more than a second, it probably would have let the Magic Smoke out.

Oh, #AliExpress sellers, where would #hobbyist #electronics people be without you? Somewhere with less excitement in their lives, I guess.

#MagicSmoke #Chinesium #fake #remarked #component #transistor #JFET #BJT #J113 #hobby