SeTec Astronomy @SetecAstronomy@hackers.town

Just found a whole batch of Hackers.town people languishing in my Follow queue.

Locals should drop me a line when following so I can approve. Not currently accepting outside follows.

#Reintroductions? But I never did #Introductions...

I'm a weird guy who decided to base his profile on the movie Sneakers. I love technology, probably more than is healthy. My interests tend to revolve in a cycle but in the spirit of hackers.town I try to keep it to infosec and general internet nerdery.

I live with a migraine 24/7 so don't be surprised to see the occasional related toot.

Fun STA Fact #4 (collect them all!): A Canadian goose once attempted to carjack me.

TFW you accidentally power off all the disks on your server.

Booted the server after the power outage last night and ... it decided that whatever was loading the ZFS kernel module for me didn't need to do that anymore. Which broke pretty much every service as all the data was on ZFS volumes.

So I got to figure out what was wrong and how to fix it when all I wanted to do was push a power button.

Garbage truck rolls up, passenger gets out, walks around, opens a hatch on the side of the garbage section, at the front. Pulls out three weed eaters. The driver then runs the compactor which apparently that was the maint. access to, as I can see some of it moving around in there. They put two back in the hatch and close it, and toss the third in the back with the garbage. And then they proceed to empty the neighbors and our trash (and our recycle, *sigh*)

Our garbage company is the weirdest

And then the power went out and all was eerily quiet.

Except for Brood X.

And a lone UPS no one can find, beeping somewhere. Perhaps in a lost room?

Tried to troubleshoot my big 12v PSU the other day, and it was fine. Thought I had imagined the problems with it.

Nope.

Used it today and after a bit it started slowly dropping the voltage again.

So that's going to be a thing that needs fixing. Kinda wish it was a hard fault, those are easier to shotgun >_>

Well, it was very much "You get what you pay for" but I got the cheapest "get it quick" car stereo that didn't appear to be all blue LEDs but had an AUX input to serve as the amp in the lab.

It's ... something. Both in terms of design and audio quality.

But it'll do for now. I soldered some banana jacks on the speaker out wires and a DC barrel jack on the power wires. Found a beefy 12v power adapter and there's finally music in the lab again.

The balance was way off balance though. I had to set it to something like Left +4 to get it to sound reasonable in the center of the room.

Whatever. It was cheap.

I give up on the stereo. There's no way I'm figuring out why the processor is unhappy without a service manual. Everything I can think of to check looks fine. I tried bypassing the power supply shutoff relay, but the processor still shuts everything else off too (like the display and the buttons and what not).

So it's been banished to the corner for now until I can decide what to do with it. But I'm going to go hit up some thrift shops and see if I can find a replacement. I don't need much. Something with two channels that physically fits in the space I've got allocated. That's really it. Bonus points if it has zero blue LEDs.

Not sure if I'll have spoons to get back to the stereo until later this week, but I'm also trying to decide if it's even worth it at this point. Sure it's a nice stereo, but I bought it used 20 years ago. It's not like it hasn't had a good run.

If I have a good day this week I just might hit up a thrift shop and see if I can find a replacement.

The idea of trying to figure out how the CPU determines how the PSU voltages are correct / how the amp is shorted is a daunting one. In the absence of a service manual I think I'd rather just say "It's done."

The alternative is to force the PSU shut-off relay to stay on all the time and see if anything blows up. If it continues to work, maybe that's good enough for it's next stage of life.

I dunno. I'll mess with it another day.

A great many years ago (10? 15?) Mom taught an interim or something in a classroom and finished out the year there. That left here with the class's aquatic frog. Lacking anything better to do with it, she took it home. It's been living in a tank in our kitchen ever since.

Friday, Mom goes out of town. I've been dutifully feeding the frog daily.

Today I drop the food in, and something doesn't look right. Wait. Where's the frog? Normally she just sort of floats around in there. She's not hiding behind her little mountain. It doesn't look like she tried to burrow into the sand. The only thing floating in the top is the silly plastic palm tree.

Mom went out of town and we lost the frog.

How do you lose an aquatic frog? Leave it to me to find a way.

I'm sure if I eat lunch, everything will be less terrible, but I *just don't want to.*

This is a thing that happens sometimes. It's not useful.

And since everything is wrong today, apparently I fell asleep watching this series, and now my progress is several episodes ahead of my memory. But not an exact known quantity. Just "several"

Welp. No more technology for me today.

I just tried to compare to XML files and managed to run my box out of memory. It has a LOT of memory.

I think I'll just lay here and watch something. That sounds safer.

Had enough of the stereo's nonsense. My attempts to rig it up to power on without all the parts involved (for bench testing) were a failure.

I think I'm going to play Space Engineers and maybe provide support for Dad's kitchen lighting improvements.

I'll fight with the stereo another day.

Got the board out of the case. Flipped it over. Ah, there's the CPU. Traced that relay control line that turns on the power supply straight back to it. Darn. For some reason the CPU thinks something is terribly wrong and the whole mess needs to be shut down for safety.

Great.

Oh, and when I looked it up, it's a masked ROM, so not going to be hacking new firmware into it or anything silly like that (which is beyond me anyway).

So, uh, I guess try and figure out how the CPU checks the PSU voltages? How it checks for speaker shorts? I dunno.

Forgot I had a photo for my terrible replacement regulator mess.

When this happens, I'll take a page out of Big Clive's book and take some nice photos of both sides of the board(s) and print them out after mirroring/flipping so they are both oriented the same. Then the colored markers come out...

I tracked down the signal that turns the main power on and off.

Near as I can tell it never leaves the main board, despite the fact that it also appears that all the smarts are on the display board.

The entire thing is going to have to be disassembled for that bit to be reverse-engineered. And in order for that to happen I need to clear a bit more bench space.

*sigh*

I JUST WANT TO LISTEN TO MUSIC IN THE LAB.

I double checked all the voltages out of the PSU while it was "under load" (the few seconds it would run) and nothing is struggling to provide the correct voltage out of the PSU. So maybe one of the interconnect cables is loose or something? Time to start probing. At least every connector is labeled with all of the signals.

Well. I replaced the faulty -12v regulator with an adjustable negative voltage regulator set for -12v. Which was fun trying to get all that wired up and jammed in there. And of course the mounting tab of the new regulator was bonded to the adjustment pin, but it was being mounted to a grounded heatsink, so care had to be taken to keep it isolated (the old regulator was in an entirely insulated case).

But it's in. It's adjusted for -11.98v, whereas the +12v regulator is at 11.97v, so I think I'm good there.

Problem is, now that everything is reassembled, the amp still doesn't want to stay powered on. It turns on, starts to check itself, and decides something is wrong and shuts off.

So now what's wrong?

What kind of a name is Bluetooth anyway? Did someone eat a marker?