Repairs

I've managed in the space of the past month or so to find the time to get quite a bit of assorted repair/maintenance work done. Some of these tasks are things I've been putting off for a while, others were responding to things as they happened. Once the ball got rolling I kind of got into the mindset and it became easy. Well, actually, it wasn't a ball I got rolling, but rather a wheel! The first task was replacing the bearings in the back wheel of the Franken Peugeot, which I had been putting off for a very long time.

The mirror bumper in one of my Pentax ME-Supers had degraded to the point where the mirror sometimes gets stuck up on the gooey foam stuff. I bought a replacement bumper off eBay. Removing the old one was a bit of a chore. I got it all off, but not without making a bit of a mess of the focussing screen in the process. I want to clean that up nicely before I install the new bumper. Oh yeah, remember one million years ago when I bought a cheap Pentax MX? I still haven't put a single roll of film through it because I haven't gotten around to replacing the light seals on it. So I bought a kit for that from the same seller at the same time, so maybe that'll happen sometime soon as well. The light meter in my other ME-Super died abruptly in the middle of a holiday about a year ago, I still need to look into that some time.

My tape deck (Technics RS-B565) abruptly stopped working a few weeks ago. I was a bit dismayed about this but it turns out to be a very common failure mode with this and similar direct-drive Technics decks. There's a plastic gear which is just friction fit to a metal shaft, and the gear tends to split with age. Once split, it no longer grips the shaft quite as tightly as it should, so it can slowly migrate along the axis of the shaft, and at some point it can come out of engagement with the other gear it is supposed to be driving. This is exactly what had happened to me. I did not need to disassemble the tape transport at all to slide the gear back to where it's supposed to be. Of course, it will eventually come loose again, so I have bought modern replacements for both the gears which are prone to this (thankfully these were easy to find and reasonably priced, I hope they turn out to be good quality!).

Since this will involve a little more disassembly I will take the opportunity to do something else I have been putting off for a long time which is to replace all the tactile switches behind the user interface buttons. Technics used a weird system for this where (if I understand things right - this is at least *approximately* correct, I'm sure), pressing different buttons connects resistors of different values to a single input pin on the control computer, and it figures out which button you pressed by measuring the voltage or the current or something. As the switches oxidise and get dusty with age, they no longer contribute zero resistance to this circuit when depressed, but have some non-negligible resistance of their own which appears in series with the fixed resistors which are supposed to determine the button function. Which means, say, you'll press the "stop" button but the computer thinks you pressed "fast forward" instead, but not always. This is, as you can imagine, pretty frustrating. Thankfully these are bog-standard 6mmx6mm miniature tactswitches, so the solution is simply to replace them with new ones, and I've bought a set of those as well. I'll spray all the pots with contact cleaner while I'm in there, of course. It will be really nice to have the deck running really nice and smoothly. I want to be able to take my time doing these repairs, though, and move slowly and carefully, so I'm putting them off until I have some vacation time at the end of this year and start of next.

Speaking of tapes, I have this diminutive little Sony ICF-SW20 portable shortwave radio, which is literally just a little bigger than a cassette tape, but is a pretty good dual-conversion receiver. It works just fine with headphones plugged in, but there's no audio at all out of the speaker. This is not actually a practical problem for me as I'd only ever listen to it with headphones anyway, but I was curious whether it was just a loose wire or something, so I carefully opened it up. I am always super nervous opening up radios with tuning indicator needles because I recall from my childhood tinkering days that it was very easy to ruin the delicate little assemblage of pulleys and springs and whatnot that make them work. I was pleasantly surprised that all that stuff was pretty well contained and just removing the case was a pretty simple matter. Alas, the speaker connections were really solid, so not sure what is wrong there.

Emboldened by this success I cracked open my ICF-7600A (which I've written about previously) because all the sliding pots and, even worse, the band switch, were crackly and intermittent and I wanted to give them a clean. Unfortunately opening this up didn't go as smoothly. The tuning indicator wasn't a problem, but the cone of the speaker is, get this, simultaneously glued to the metal frame of the speaker, from behind, but also the metal grill on the front of the case, from above. In some areas, one of these glues held stronger than the other and I found myself in a really awkward situation where the speaker was slowly deconstructing itself as I tried to gingerly remove the front panel. In the end I got it off with relatively minor but definitely visible damage to the cone. I was kind of grumpy about that, to be honest. Seems like a bad design? Anyway, it was easy to clean all the pots and switches and everything works nicely now. I put the speaker cone back together as best I could. Once again it doesn't really matter as I only use the things with headphones anyway, but I was pleasantly surprised to notice that the audio out of the speaker still actually sounds great despite the damage. While I was in there I noticed that the ferrite rod antenna used for MW had actually snapped in two at some point. I'm pretty sure there's been a slight rattling sound in that radio ever since I bought it, I actually always assumed the speaker was slightly loose or something, but this was the cause. A little bit of super glue took care of that.

In some ways all of these tasks are, obviously, chores and inconveniences. But there's something kind of satisfying about caring for finicky old things as well. At least when it goes smoothly!