Test Equipment Anonymous

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Just like the title sez:

What did you break, scorch, zorch, let the magic smoke out of or percussively triage to death today?

Cases of self-defense technicide in preservation of one's own sanity and just plain "It Needed Killin'!" are also welcome here; just be truthful in the tale...

mnem
...with us and yourself.

I'll buy that on a Tee shirt.

tautech wrote: ↑Mon Dec 05, 2022 2:51 am I'll buy that on a Tee shirt.

Fairly easy to get that printed on a t-shirt nowadays.

Personally I'd like to be able to show it to a typical "technical" CSR, pointing out I'm sufficiently experienced that I usually skip to 5 and in some cases to 6..

tautech wrote: ↑Mon Dec 05, 2022 2:51 am I'll buy that on a Tee shirt.

Which... "6 Stages of Debugging", or "It Needed Killin'!"...?

mnem
"I prepared EXPLOSIVE RUNES today..."

mnementh wrote: ↑Mon Dec 05, 2022 1:43 pm

tautech wrote: ↑Mon Dec 05, 2022 2:51 am I'll buy that on a Tee shirt.

Which... "6 Stages of Debugging", or "It Needed Killin'!"...?

mnem
"I prepared EXPLOSIVE RUNES today..."

Hmmmm, well both of course which as knowing me would make perfect sense. Didn't really consider the Killin and probably would tone it down by being more specific like 'The vermin needed killin' for this OTT PC world.

mnementh wrote: ↑Mon Dec 05, 2022 1:43 pm
"I prepared EXPLOSIVE RUNES today..."

I initially read that as "I prepared EXPLOSIVE PRUNES today..."

I can't unthink the resulting image!

mnem
start a movement; eat a prune.

Well, fuck-a-diddly-doo... 3 times I've removed this digitizer without harm; in fact, it is the only part that remains of daughter's original 6th Gen iPad.

Recently it started acting funny; sometimes difficult getting it to enter numbers when signing in, so I decided to try removing it and reinstalling it with a double layer of sealant tape, in case it were warped or something pressing on it. 4th time was the unlucky charm; got 3/4 of the way around and it just went "ka-toink!"

I figured it couldn't hurt to try the double-layer thing as the screen-protector was still intact... but she must've whacked it across something cuz now the protector is cracked in 2 places too, with 4 symmetrically-placed chips in the edge.

The really suck part is that now, the digitizer appears to work perfectly.

mnem
*toddles off to spend more money on fleaBay*

I'm mucho pissed off at the replacement top case half/keyboard I got in for my Lenovo Flex 3.

Assembled the unobtanium LCD from the original cracked screen into the new TS digitizer/bezel and wonder of wonders, I didn't crack either part.

Even more glorious, it all actually worked when I plugged it into the mainboard on the bench for testing the entire LCD/TS as an assembly.

Installed the LCD assembly and main board into the new top case half, and... Wahh, wahh, wahhhh... No chooch.

Tried plugging in the AC power brick, and something is getting hot in the VRM area. THAT thing. Gets hot in a few seconds after plugging in the power brick, even with no battery plugged into an otherwise bare board.

Something in that new upper case half wasn't insulated like it was aspoda be, and shorted my shit out.


mnem


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https://www.ti.com/product/TPS51275C

Hmmm... research indicates it is a TPS51275C in QFN-20 package. Looks like a dual 5.5V/3.3V x 20A LDO buck converter. Obsolete, but pin-compatible updated equivalent parts do exit. I see a number of China-direct vendors offering it on eBay... but given the high current rating, I think maybe I need to do some more troubleshooting and make sure the cause isn't a shorted something else downstream.

mnem
*toddles off to ded*

https://www.ti.com/lit/gpn/tps51275c

Took me 3 hours of diag, but I finally found the source of the short; some skeevy Asian pimpdaddy Nuvoton keyboard decoder/power management/what-the-fuckever chip.

Fucking datasheet is pure unobtainium; closest I could find was a "internal CSM use only" schematic from some old Acer laptop that used the same little gawddammitt chip.

Of course I can buy the chip from DHLgate... But I don't know if it has to be programmed to be a Lenovo what-the-fuckever-it-is...

mnem
smeesh.

Soooo... Add one part klutz-ass tinkerdwagon, one part 48V/148WH power cell and one part gravity, and ZZZZZZORCH!!!


I was doing charge-testing on one of three common-slot server batteries I'm working on as a upgrade for my eBike... actually managed to knock the (+) probe out of my hand with the probe already on the (-) rail; gravity took care of the rest with surgical precision. If you look at this pic after I cleaned the jank up with brush & IPA, you can see it burned through the upper (+) rail, and then took a bite out of the 2nd (+) rail underneath.

Ahh dunn futt itt up good.

You may now all point and jeer.

mnem

bd139 in Discord wrote:

don't throw the probe away!

keep it to remind you what a steely eyed, steady handed, electronic genius you are.

(most times as i head down to the bench swmbo says......."don't burn the house down dumbass")

Yeeeah, I've already ground a fresh point on the zorched one; the Dremel was right there on the bench with a diamond wheel on it, and I'd have to get up and walk all the way to the back wall for another set of probes.

Eff dat.

mnem
I will probably solder a sewing needle to it sometime when I get bored...

Yep, I second that approach, why waste energy grabbing another set of probes when you know that you're gonna grind another point on it later rather than throw it away, f*** that for sure