Cassette Deck Repair, Round 2

When last I left you, dear readers, I was stymied in my attempts to transplant a broken gear in a Tascam 112MKII audio cassette deck with a healthy replacement. A few tiny, inconveniently placed screws were stripped such as to prevent getting to the heart of the matter (or the deck). I investigated some options for purchasing screw extraction bits for our power drill, and have indeed added those to my box of toys (*cough* I mean tools) since.

But I am not a patient man, which meant I went in for another round of futility because hey, what am I going to do, break the deck more? (I mean yes, I absolutely could do that but THAT IS NOT WHAT THIS BLOG IS ALL ABOUT). After failing at the so-called “rubber band method” (I just have a bunch of rubber bands with screwdriver-tip-shaped holes in them now), I took the suggestion of one of our Cinema Studies PhD candidates and applied a vice grip.

Pictured: overkill.

Leverage was near-impossible when trying to turn a 3mm-wide screw with a giant vice grip at a weird 45-degree angle. Yet somehow, yes, I was able to loosen the stripped screw enough to get in there and manually twist the dang thing out. Surgery back on track!

…and after! Note that this is actually gear assembly cover removed from the “healthy” 122 mechanism, because I took that apart first because I do sometimes learn things.

Now able to remove the cover housing the gears for the playback mechanism, I could finally get to the clearly offending piece of the puzzle. Yes, it is difficult for your cassette deck to keep running when one of the delicate plastic pieces inside literally cracks in half:

I know you guys might not know a lot about audio cassette decks but surprisingly this is a problem. Whoda thunk.

At first, since it was such a clean break, I did idly wonder if I could just super glue the broken gear back into place, and even made a quick stop at the hardware store around the corner over my lunch break (as is my approach to most tools or supplies, I tend to just try to buy whatever I can think of, under the assumption that even if I end up not needing it now, it will almost certainly prove useful at some point later). I don’t know how archivally sound the combination of Krazy Glue adhesive is with whatever plastic this gear is made out of (it almost surely wouldn’t have held up for another couple hundred tapes), I realized that the point was kind of moot, because even past the obvious, giant chunk of the gear that had snapped clean off, less noticeably the teeth on the smaller inner part of the piece had also been totally worn down, and were also likely not catching properly in the mechanism.

The cassette deck just CASSETTED SO HARD this gear couldn’t take it

So, back to the replacement part then. Going back over I tried to take out the healthy gear from our backup 122MKIII…

…a process that literally took about 30 minutes. See, all I had the do was lift the gear out – but whatever lubricant had been placed on the gear shaft of this deck had morphed, over years of disuse, into a pretty strong adhesive. That gear was stuck tight, and, considering the broken-in-half example right at my disposal, I had a hunch this piece was kind of fragile. It would be pretty useless to snap a gear while in the middle of replacing a snapped gear, so I had to be extreeeemely patient and just ever…so…gently…wiggle the gear off the shaft, most of the time never apparently doing anything at all (in fact, if it hadn’t been for the fact that the broken gear lifted out so easily of the 112, I probably would’ve assumed I was doing something wrong with the intact one).

Now stop – Wiggle Time.

But, once that finally came free and I took a minute or two to revel in the satisfaction, I was finally able to piece back together the gear assembly on the 112, and a few manual turns seemed to confirm that the motor would now spin correctly. By all outward appearances, this was a successful transplant and I hurriedly packed the tape transport unit back into place to test my handiwork. For one brief, shining moment, as I pressed the Play button, the motor whirred, the gears turned, and all sounded healthy as the tape started moving forward at normal speed and the meters bounced.

Then a second later, the head assembly kicked out of playback mode. Trying again, the same thing: playing back fine for a second, then the system automatically refused to keep going.


Unlike last time, there were no hideous noises emanating from the deck, and the lights on the transport buttons on the front panel were not freaking out. The lights on the programmable buttons (RTZ, LOC1, LOC2, etc.) were now constantly on – but I could not tell when exactly that had happened, and in any case they still appeared to be responsive (I could set a zero location, fast-forward the tape, and then automatically return to that location, for instance). So that seemed unrelated to the tape refusing to stay in playback mode.


After a few more repeated tries I still couldn’t figure out what was happening, so I hit eject to remove the tape and take another look at the transport mechanism in case I missed something – which is when I saw this:

Bad tape! You’re not supposed to stay outside your cassette past curfew. You’re grounded!

Hmm. Why was the tape loose in the cassette? Winding the tape back tight (oh how long has it been since I had to manually wind a cassette with my finger? too long, for this ’90s kid), I took a closer look at the cassette itself as I attempted playback. At which point I saw that when I hit Play, the supply spindle (the side of the cassette on which the tape is wound) on the cassette would start spinning, but the take-up spindle (where the tape winds after passing over the heads and playing) refused to budge – meaning that after passing over the playback head and through a pinch roller, the tape would just sort of loosely dump into the cassette for a second or two, until the pinch roller presumably detected that it had lost tension and automatically kicked the head assembly out of playback mode, to protect the cassette and the deck from getting damaged by out-of-control tape.


And that, essentially, is where I am stuck right now. The take-up spindle has no obvious motor driving it, and I am pretty confident I didn’t damage that part of the transport unit during disassembly – although, given the fact that the 122, which I am essentially using as a model of what the mechanism on the 112 should look like, doesn’t spin at all, I can’t say that for sure. So why is it not turning during playback? The only thing I can think of is that somewhere in the transport unit is a sensor that communicates with the take-up spindle that I somehow mucked up – although, again, the spindle turns completely normally during fast forward and rewind. And if I actually sit there and manually spin the take-up spindle, playback continues normally. But that is not exactly the most practical solution, since I have, you know, at least some other work to do.

If anyone has further suggestions, I’m all ears, but at this point I’m further investigating backup decks and probably bringing in a more experienced audio technician to perform a repair – at this point I would at least have a very specific issue to bring to them, which would hopefully keep the repair quick and therefore relatively inexpensive, since freelancers charge by the hour.

Cassette Deck Repair, Round 1

A lot of the equipment I work with is shared between the MIAP program and the Cinema Studies department’s Film Study Center archive. As one of oldest film studies programs in the country, NYU has been acquiring movies for screening and teaching purposes for decades, so we’ve amassed a considerable collection in a variety of formats (though the content may not be overly unique – there’s a lot of copies of, say, Taxi Driver). We also house the department’s internal records, which includes a lot of audio and video recordings of lectures, conferences, and other events hosted by Cinema Studies over the years. These archival materials often offer me a sort of testing ground for equipment and resources that will end up getting demonstrated in MIAP classes. This is extremely helpful, given that archival education needs to be very hands-on, and as much as MIAP does a fantastic job of teaming up with other cultural institutions to get that direct experience, having in-house opportunities to practice what we preach is invaluable.

We’ve been slowly reformatting our audio cassette collection for at least a few years now on our Digital Audio Workstation (nicknamed “Bigfoot” with affection?). We run on a workhorse Tascam 112MKII cassette deck, patched into an Analog-to-Digital Converter and capturing preservation-level audio files (uncompressed WAV at bit depth of 24 bits and 96kHz sample rate) in WaveLab 8. It’s slow going, since you have to capture audio in real time and we’re only running the one deck, but it’s a great project and there’s some really cool material I hope we’ll be able to make available some day.

But we hit a hitch last week when our reliable old Tascam deck broke down. Tapes would still safely rewind and fast forward, but hitting the play or pause buttons started producing discouraging sounds and a full-fledged freakout from the lights on the front panel display, after which the tape would either come to a full stop or start playing through at high speed.


The loud clattering noise and the fact that the buttons were still responding, if not functioning normally, gave me hope that this was a mechanical issue and not electronic – as I mentioned in my first post, I’m woefully inexperienced with circuit boards or sussing out electronic signal issues, but mechanical issues are usually far more visible and therefore diagnosable, if you’ve got the bravery and some spare parts (or creativity).

But this was nothing that I could fix as long as the Tascam was still mounted on our DAW, so my first priority was to set up the students working on this digitization project with an alternative deck while I took out the Tascam for some TLC.

I’m sorry, Bigfoot.

We had a spare Tascam CC-222 in one of our back rooms, which was originally intended as a cassette-to-CD dubbing machine. The transport worked fine and the signal was acceptable (we’re not overly concerned with preserving the quality of these tapes per se – honestly they’re pretty rough recordings to begin with – but the content is super), so all I needed was some RCA-to-TT patch cables to get this auxiliary deck running. The digital meters are unideal for monitoring compared to the Tascam’s analog meters, and it’s essentially impossible to calibrate (there’s no easy way to adjust the angle of azimuth on the playback head, for instance), but it’ll do for now.

That “No Disc” warning has probably been on since 1999.

Meanwhile I did some more digging and found we had a Tascam 122MKIII sitting in storage – a model almost exactly the same in mechanical design as the 112. When I hooked up this deck it was completely unresponsive, meaning there’s probably an electrical issue and I could feel pretty safe in condemning it for scrap – with luck whatever mechanical parts were broken in the original 112 would still be intact on this spare 122. Time for a transplant!


Opening up the cover on the 112, I could now visibly observe the issue with the transport unit rather than just listening. The clattering sound was mostly coming from a fitful spring, but that didn’t actually seem to be the problem – tracing the motion back through the unit, I could finally see that indeed, one of the gears connecting the transport unit’s motor to this spring (which in turn lifted the deck’s playback head up to make contact with the tape path during normal “play” or “pause” mode) was broken. Glancing over at the 122, it had the same gear – in one piece.

So far so good – but now, how to get this gear out?

I wish I could be a little more specific here, but honestly even with a service manual at my disposal, the only strategy ahead seemed to be to start methodically unscrewing everything in sight – or even out of sight – while at least avoiding messing with the motors.

This asshole right here took a solid 10 minutes alone.

Now someone with a little more foresight might have started disassembling the backup 122 deck first. After all, that’s the scrapped deck anyway, right? I could mess up that machine however I wanted and it would make no difference. But no, for some reason I plowed ahead, fiddling with the 112, apparently operating as if the broken gear was literally cancerous and the disease would spread to the other gears if I didn’t get it out IMMEDIATELY.

What this meant is that halfway through disassembly, which was already a laborious process thanks to my apparently less-than-steady hands and their tendency to drop tiny screws into the bowels of the deck…

*Is it water on the knee? Oooooperaaation…*

…I realized that I was entirely unsure if I would ever be able to put this thing back together correctly even if I did manage to reach and replace the broken gear. Indeed, just idly trying to fit the transport unit back into its original place in the deck, the eject mechanism was now stuck, and it was entirely unclear if the pressure pads (which sense a tape is in the deck and allow the transport buttons to work) were still functional.

Hard to see, but this thin metal piece should not be there. Why is is there now? Absalom, my son, what have I done?

So that meant a couple painstaking hours of, essentially, reassembling the deck in order to fix the damage I myself had impatiently inflicted – never mind the original problem that I had set out to deal with. Which, by the way, it turns out I couldn’t have dealt with today even if I’d wanted to – one of the most essential-to-remove screws, holding the gear mechanism in place, is totally stripped, and in a very awkward position to get any leverage with a screwdriver. So the upshot of all that is a detour while I try to purchase a screw extractor drill bet set for our power drill.

I mean for real how did this even happen?

Chalk that up as a learning day. At the end of it all, I at least now have a much clearer idea of how to remove the transport unit as a solo piece from the deck without interfering with its mechanical function. That is, I should be able to access the broken gear this time without taking away the machine’s ability to eject or communicate with the front panel buttons. And I will do it all on the 122 first – to make sure I have a healthy heart before cutting out the bad one.

“Kali maaaaa…kali ma shakti de….”