I got a broken MiniDV camera pretty much free for the asking and took a look inside. Well, I’m glad I didn’t go in expecting a successful repair because oh no
Probably 50% of the weight of this thing is tiny screws.
I was intrigued and horrified all at once that a tiny cog belt was visible! See it peeking out there to the left of the rubber pinch roller?
The iris was stuck closed. I’ve seen this failure on a few JVC mini DV cams and had never opened one up to investigate. Upon seeing the mechanism I’m not surprised this happens. It’s a combined aperture and ND filter with two weird thin plastic blades that have stuck together, actuated by a very tiny rotary solenoid.
So there’s the tape transport, it has only two motors aside from the head scanner. A very small pancake capstan motor is under the side where the pinch roller is; the one standing in the corner controls the load/unload action.
And finally, that tiny cog belt runs between the capstan motor and a pulley that drives the gear idler. The tension is regulated by a spring loaded brake (felt?) under the take-up reel and that’s pretty much it. This isn’t exactly a very sophisticated transport.
I can’t really imagine actually repairing one of these. Everything had to come out to get to the back of the transport and it’s a total mess in there. Wow.
Out of curiosity, I pried apart a laser pointer from Dollar Tree. See that tiny spot next to the blob-top circuit (probably the current regulator/driver)? That’s the laser diode.
I really want a microscope now to see what the heck is going on here!
There’s a lens to focus this into a more, uh, pointer-like beam. I haven’t figured out how to photograph this well yet but the uncollimated output is a wide elongated ellipse of light with pond ripple patterns at the ends.
For some reason I always envisioned the common laser diode to be a bigger object, but no— it’s teeny weeny. Cool.
After months of neglect, I redyed my hair. Interestingly it seems like the blacklight at my workbench has become…. a dim purple light. The UV emission appears to be mostly gone. I’m not surprised as this has always been a common failure mode of uv led emitters. A lot of plastics that are common in other LED carriers will degrade from the UV and begin to absorb it, letting through only the visible blue/violet color, if much at all. The bulb has been on 24/7 pretty much ever since I started doing rainbow hair so it’s given a good service life. It occurs to me that one of my coworkers who just came back to the office today has never seen me with rainbow hair before, and he didn’t say anything about it…… but he suddenly decided he’s now tired of only wearing black clothing! Well then… I’m glad to be bringing more color to the world. :3
There are visible black spots on top of the LED emitters in the “filament” now. I don’t remember if they’re that way on these bulbs new but I’ll compare them when I get a new one. That is assuming I don’t just get some UV LED tape for my workspace where I sit and yell about things like these cursed faders in a JLCooper audio controller.
A lot of equipment with motorized faders has pretty similar faders, but these are all weird and look almost like a totally custom bizarro construction. They’re not Alps, Penny & Giles, or Midas, they’re just weird and we kill them every year and change. Uh, okay.
The hardest part of having false hope is when it all falls apart. Here, I’d been told that the PowerCD transmitter that I lovingly call the Space Station Toilet was going to be replaced starting in April or so.
Oops. Turns out nobody has any of the required supplies for that project in stock anywhere and production isn’t expected until July at least with an estimate on replacement being maaaaaybe September… and every tiny setback adds another fortnight of business days to the backlog. Time to start making this thing as happy as possible to prolong its final year (or decade?) of service…
Another adventure at the Space Station Restroom standing tall in a field by the river… This is cabinet #1 of 3. Cabinet 3 was the one that gave me such elegant fits before when I did a grid scrub. Cab 1 wasn’t causing as much drama but it just wasn’t making enough power prior to the scrub and was occasionally arcing out, roughly once a day. Let’s gooooooo to the wash!
Yes, of course it keeps trying to flip back to BG Heat every few minutes so you just have to stand there in front of it and pwap the standby button each time. Annoying. I thought about just raising the filament voltage in BG Heat but realized that’d be a terrible idea as the cooling system shuts down when you’re in BG Heat! I can’t remember if the air blower eventually goes down, but the water pump definitely does.
As I prepared to do the grid scrub (which requires hooking up an external power supply to the ESCIOT tube grid and cathode), I went into the high voltage cabinet with some isopropanol and blue shop towels and did a, well, scrub.
What’s that now? Oily sticky gook…. just like I found in the other cabinet? Hmm. I’m beginning to wonder if this is ethylene glycol that’s been electrostatically precipitated out of the air, since this rig is known to absolutely REEK of Dowtherm SR-1. The recirculating pump/reservoir unit is far from airtight so it just outgasses.
And now, Deja Moo: the feeling I’ve seen this BS before—
Look at the upper left: this robot has seen some shit, man
Amazingly I did not find it necessary to readjust the grid voltage after the scrub, it just… Worked. I was not expecting this. Not out of this turdly transmitter.
Then came the surprise. I was walking past checking the coolant system pressure on the pumps for the other transmitter in the room (a rather boring solid state ULXT-80) when I saw one of its variable frequency drives blinking “OCL”. Interesting. I first foolishly decided to take the cooling fan cover on the TEFC pump motor off, thinking I was going to find a seized pump. I spun the fan and found no unusual resistance. Upon opening the cover over the drives I was greeted by….. toast.
Not sure what went first, the screw terminal or the crimp forked terminal that was stuck in it, but something got hot until it cratered the poor drive. Ow! And to make matters more fun, as is always the case nowadays…. nobody seems to have these drives in stock anymore. Luckily, GatesAir has them, for about the same price as a better quality Fuji Electric drive from Grainger. Hmm. Do I…? I’ll have to make sure the Fuji has the right I/O first before doing anything that daring. On a side note, if GatesAir is going to charge that much for a drive they marked up like 100% they could at least take it out of the box and program it for you. They do not do this.
Then again this is the same manufacturer that charged us about $500 for four small rubber washers that I strongly suspect were just pieces of EPDM rubber hose cut carefully to length.
It’s my personal opinion that these Toshiba drives are built like damn toilet paper. They were only common in everything because they’re cheap and have tons of I/O options. Bad power will murder them in no time. It didn’t even get a chance on this one as thermal runway at the terminals Popped It.
Well then, all that resolved, it was time for the last silly task of the day: go see why the surveillance camera up top was giving us no usable image….