Tested but not tested?

I guess the Chinese quality control method of “the customer is our quality control” has been inherited by iBuyPower.

Still, they manage to be one of the very few off the shelf systems we can still buy locally that uses standard components.

Dark absorbent

I got a box of LED light bulbs at the local DumpshitMart and the first one I pulled from the box was a dud but flickered several times as I screwed it in. Strange. I suspected a bad solder joint, and noticed the bulb part felt like plastic and not glass.

I started prying on it a little and it popped off revealing the emitter board.

Interesting construction. Spring contacts are used for the capacitors, and presumably for the power input. I noticed right away that one of the power input pins wasn’t visible in its terminal.

I wonder what these regulator ICs are? No visible inductors are present (and I can’t see any signs that they used a multi layer board with a pancake inductor) so it’s not a buck converter. Might just be a linear constant current driver or something.

16 LEDs in series assuming Vf = 3.2v each would be an operating voltage of 51.2v. This would imply that either those led packages contain more than one diode in series, OR most of the voltage is being dropped by the current drivers!

The two caps behind. Strangely, once you’ve unglued the bulb, these would be the easiest caps to replace that I’ve ever seen. They’d just slide right out.

I didn’t get a picture behind but all the bulb needed was for the lead wire to be pressed back into the terminal. I didn’t have the same white silicone goop the thing was assembled with so I just used silicone gasket sealant to stick it back together and returned it to service.

I took this before gluing the bulb back on. Operating the bulb like this in an open fixture, as nice as it looked, would likely lead me to accidentally stick my fingers into it. I’m very prone to accidentally sticking my fingers and hands into the ceiling fan. I’m working on my Horrible Klutz merit badge, you see.

Interestingly this bulb has the metal heatsink cone for a base that I was used to seeing on earlier LED bulbs, it’s just covered in plastic. This kinda implies that their bulb just doesn’t dissipate much as heat and possibly that the metal core circuit board is not acceptably (or not at all) electrically isolated from the AC line voltage to allow it to safely remain exposed.

The old LED bulbs with the huge heatsink fins are noticeably few and far between, after all. They’re getting pretty dang good. Now can we have some build quality??

I love Behringer. I love them so much.

why you may ask? because they make audio FULL OF SURPRISES

Plugged in power to a Eurocom SPL3220 that had been sitting on my shelf a few months and it went snap! tweet! and went dark. These DECON capacitors are lovingly referred to as “rat poison caps” after the D-Con brand pest control products, and they are pure garbage. These are just used for dc blocking on the audio inputs and outputs though.


So is this some kind of weird joke or… just dumpshit? CoolAudio is a company under Behringer’s parent “Music Group” company and their website proudly advertises a bunch of chips they market as being functionally identical to a number of other audio ICs by Cirrus Logic, THAT Corporation, etc… but probably just super low quality dumpshit they had fabbed up to compete only on the basis of price.

I’m guessing the pop and screech came from one of the “CapXon” brand Taiwanshitlytics on this SMPS board but it’s only Monday and I’m already tired of this shit ok






there are no words. Someday I will try to come up with words in the process of writing a notice of retirement, but that day is not today.

The really fucked up one is an Armstrong tube transmitter from the mid 1990s.

The tape wadded splices are in the ~8000 volt plate supply. Also in this collection, a Nautel that ate a BNC lead that then ate several expensive RF transistors.

🎶 I am barely breathing, I can’t find the air 🎶

PissTek Again

We had some crazy winter storms and the site I lovingly call Shit on a Shingle lost power. When the power came back after a couple days, the station didn’t.

Found this little derpshit howling away as usual with no output. Front panel buttons and remote interface were unresponsive. Power cycled it and the controls came back but still no output. I warmed it with a space heater for a while and if fully returned to service.

I know some transmitters don’t like extreme cold, but this thing had only reached about 34 degrees at the lowest.

It had a really shaky start too, the front panel indicated 1750 watts forward 0 reflect, but no PA current, and it wasn’t audible on the air. I set it to 500 and it was audible for about a block down the road. As incoming snowstorms chased me from the site I heard it just gradually chatter and wheeze back onto the airwaves.

Hello, Transmitter Fairy, what do I have to leave under my pillow for you to leave me a nice Nautel VS2.5?

Please don’t disturb the kitty on the pillow.

This is, incidentally, the same site where the combiner horror used to live. Yeah, that one that never worked at full power until the whole system was sent out for service for a few months then exploded after less than a day on air.

Mmm, Galvanic Corrosion Burger

I don’t know where they came from but somehow this facility was ~blessed~ by having some aluminum transmission line adapters in use.

Here’s one (a gas block with pressure fitting) sandwiched between flanges made of brass and nickel plated(?) brass…. similar to about 99% of all these fittings I’ve seen in service.

But wait, aren’t those a little far apart in galvanic potential?


To the tune of Sisters Of Mercy – This Corrosion

Gack. Note the first inner lip around where the polymer insulator is seated. This is where the RF connection is actually made. The well around it only holds the sealing ring.

No thanks.

Broadcast Engineer: (n) A person who fixes all the shit the manufacturer fucked up by design.

Let’s play Wheel of Dumpshit!

Tonight’s contestant: a Lutron dimmer switch.

This switch was pulled from a studio after it made the lights flicker. Sometimes tapping it would change this but moving the slider didn’t.

Let’s see what’s inside.

Well that’s unusual. A small snap switch is used behind the lights on/off toggle. But wait, aren’t those momentary switches? Clearly a mechanical latch is used. Let’s see that latch….

Wait just a NOPEing minute. They used a cheap and nasty no name Chinese latching push button to latch the light switch…. and it’s worn out and gotten loose, letting the snap switch flicker.

Let’s have a look at the actual switch contacts. Hmm, that switch smells funny and the Bakelite fractures very easily….


This could have caused a fire if it were powering a high wattage bunch of incandescent or halogen lamps.

Yeeeep, it’s dumpshit. Thanks for playing.

Heat block nonsense

The stock heat block on the Malyan (200?) / Monoprice Select Mini v2 3d printer is a special sort of awful. Out of the box I had weird issues. PID autotune would fail with a “Temperature too high!” error, and I threw various sets of PID values at it to no avail. What’d happen was every time the heater came on, a 5 degree C overshoot was virtually guaranteed, leading to lots of print stringing. It almost seemed like the temp would rise for about TEN SECONDS after the heater shut off. I suspected poor thermal coupling between the heater cartridge and heat block, and ordered a $10 E3D V6 clone off eBay intending to just use the block it came with.

I wound up doing just that.

The E3D silicone sock even almost fits it! Uh, not great though. I cut away one tab to make room for the thermistor retaining screw.

And now, on to the block of horrors. It had this execrable kapton / fiber covering that disintegrated when touched.

Bad picture but you can already see it looks rough, right? It gets worse.

There’s the heater bore. It doesn’t look like the hole was drilled as much as ice picked.

The grubscrew that locks the heater in place, and the questionable looking threads for the nozzle and heat break…

Seems to me the whole damn thing was a heat break 😉

Yeeeeah, so I haven’t fine tuned it with the new block in yet but just switching the heater on at the front panel and watching the temperature reading, it ramps up and just locks in with occasional undershoot of maybe 3C. Much better… Maybe the PID tune will even work now!

I thought these were just a bad fever dream

Maxtor 1/4 height 3.5″ drive. I forget the name for these but they were some of the least reliable hard disks ever made. One very odd aspect of this design (possibly contributing to the problems?) is that it only uses one platter and only one side of the disk!

The head stack is comically simple … one thin film write head and one MR read head.

These drives usually lasted a year or so in service then provided a brief period of degraded super slow service during which you could save some data…. Then they’d up and die.

These images were saved to a Samsung micro SD card with about three times the capacity as the drive pictured which has been in service for about five years.