With apologies to Song of Solomon, 2:12. But surely the blog title makes at least as much sense as ” .. the voice of the turtle … “. Whatever. This post isn’t about Bible specifics.
The background here is that a friend, has a little kid, who really likes a stuffed toy, that has a broken electronic voice-box.
The catch is that the toy in question is a 25-year-old plush chihuahua dog. It was a promotional giveaway from Taco Bell. It was never meant to be repaired.
There are probably a lot of these exact Taco Bell chihuahua dogs still in existence. You can buy one on Etsy (below). But at this point, it’s a fair bet that the 25-year-old batteries in the device either have died, or will soon die, if the toy is actually used as a toy. So if you want one that talks — and the little girl in question definitely wanted that — you’d best be prepared to replace the batteries, at least.
Source: Etsy (link to page).
So, would I mind trying to fix it? Needless to say, replacement parts may be an issue. And in terms of helpful instructions on the internet, I found none.
In the end, I tried to fix four broken Taco Bell chihuahua voice boxes. You never know who might want to read about fixing a mute Taco Bell chihuahua plush toy. So I thought I’d document the fix. It’s not as if hordes of folks read this blog, even on my best days. Bottom line, three out of four now work.
Yo quiero Taco Bell.
The first step is to remove the voice box from the toy. The little girl’s mother did that part. It boils down to carefully splitting a seam, fishing around in the toy, and removing the plastic voice box. That’s the white box, front and center, below.
Above you see the white plastic voice box, surrounded by the tools needed to fix it. These are, left to right:
- Screwdriver set with assortment of oddball bits (more later).
- New batteries (requires three LR44 a.k.a. AG13 or G13 or A76)
- Optionally, if the old speaker is broken:
- a new 0.25 watt, 8 ohm, 27 mm speaker, such as this speaker on Amazon.
- soldering gun/iron and solder.
Step 1: Open the case. The voice box is held together with two screws. Some internet instructions say these are #6 Torx. There are clearly manufacturing variations across these voice boxes, so it’s possible some use Torx. Mine did not. My case had screws with triangular sockets requiring a 2 mm “Y” or “tri-wing” bit for removal.
Above, left to right, you see the case with the top off, you see a blunt object pointing to where you have to pry, and you see the board, once it is loose, revealing the batteries.
Step 2: Gently move the circuit board. Note that I did not say remove. (See speaker, below, to understand why.) The circuit board is held into place by clips that also hold the batteries in place. Get a thin, blunt instrument underneath the arms of the circuit board that hold those battery clips, and gently pry up, alternating sides until the board comes loose.
If the battery connections on the circuit board are cruddy from battery corrosion, clean them as you normally would. I use a piece of fine grit sandpaper. Others use chemicals. Doesn’t matter. You just need a bit of shiny metal right where the circuit board contacts the batteries. If you have a volt-ohm-meter, you can double-check to see that you have a good connection by putting the batteries in, putting the circuit board in, and looking for 4.5V between the tops of the two battery connection terminals.
The circuit board is simple, but, oddly enough, out of four voice boxes, I saw four different circuit configurations. Sometimes there was an extra resistor, sometimes there was a tiny little electrolytic capacitor, and so on. I can only guess that each different phrase the dog could say somehow required a slightly different circuit? Beats me. All I know is, I expected four identical circuit boards, I got four mostly-similar circuit boards.
Step 3: Replace the button cells. If your only problem is dead batteries, then you are practically done. This unit takes LR44/AG13/ etc. alkaline batteries. Note which way the batteries sit in the case. As oriented here, with the batteries to the right, the flat (positive) side of the button cell faces downward. Now dump/gently pry the old batteries out, put some new ones in, reassemble, and you are done.
One of the four boxes I’ve done had a small metal “spacer” disk in the battery compartment. The others did not. Do yourself a favor and just throw that spacer disk away. I’m pretty sure it’s not needed if you buy standard AG13/LR44 batteries. (And if you put it back in wrong, you can short-circuit a couple of batteries, which is a bad thing to do.)
Step 4, optional: Dealing with a broken speaker. The box and circuit board are pretty rugged, except for the speaker. The speaker is a thin plastic membrane driven by a coil of hair-thin wire. Worse, the circuit board is hard-wired to the speaker sitting below it, so you stress all those mechanical/electrical connections when you move that circuit board. That’s why you should move the circuit board as little as possible, if all you need to do is replace the batteries.
In any case, on two of the voice boxes I fixed, the solder pad for the speaker pulled out, breaking the hair-thin wires in the speaker itself. That repair then required replacing both the batteries and the speaker.
Above, you can see the circuit board with the broken speaker solder pad hanging in mid-air, next to the old broken speaker and a replacement. This is a 0.25 watt, 8-ohm, 27 mm diameter speaker. Note that these speakers are sold in 27 and 29 mm diameters, and you need 27 to fit back into the case. These speakers are still a common commodity item. Here’s a link to the Amazon listing for the one I bought.
I won’t go into the details of soldering, other than to note that my soldering kit is so old, I have a roll of vintage Radio Shack rosin-core lead based solder.
I suppose I should be concerned about using that. And yet, I am not, mostly because I grew up in the era of leaded gasoline, an environmental disaster that literally and permanently materially reduced the IQ of an entire generation of Americans. Leaded gasoline still accounted for the majority of motor fuel consumed in the U.S. through the mid-1980s, and leaded gas wasn’t banned entirely for on-road use in the U.S. until 1996.
To me, this explains a lot about how America functions with the Boomers running the show. This is why I truly believe that generation is going to have to die off before we can return to sanity. At some point, I’m going to have to do an entire post about things that young people do not believe could possibly have been true within living memory. E.g., everybody smoked everywhere, and ashtrays were standard in cars. And we spiked our gasoline with a toxic heavy metal, solely so that we could make use of cheaper grades of gas. (Tetraethyl lead raised the octane rating of gasoline, at the cost of spewing lead out the tailpipe, along with the rest of car emissions.)
Anyway, solder the two wires to the two copper soldering pads on the speaker, as shown above. Doesn’t matter which is which. Doesn’t matter how you get it done. My preferred technique is to melt a blob of solder onto the tip of the gun, then hold that blob on the wire/solder pad for a bit. Then remove the gun and hope everything sticks that should.
Assuming all goes well, place the speaker back in the case and replace the batteries. At this point, depending on which box you got, you may need something to use as a spacer between the speaker and circuit board, to keep the speaker in place. I used a bit of cork, but a small wad of paper would also work. Then, clip the circuit board back into place over the batteries, screw on the cover, and you are done.
Addendum: Replacing the transistor? Just don’t go there.
These simple battery/speaker repairs restored three of the four voice boxes I was given to work on. But for the fourth one, no joy. After checking for a known good speaker (8 ohms across the terminals), and checking for power (4.5 V, as noted above), the only other plausible failure point, that could readily be replaced, is the transistor.
If you are crazy enough to go to this amount of effort, you can try replacing the transistor.
But ponder this: On Etsy, as this is being written, you can buy a used non-functioning Taco Bell chihuahua voice box for $3 each, plus shipping. And the voice boxes come with a free throw-away plush doll attached.
So before you dive into replacing that transistor, as a guess, on the off-chance that the transistor has blown, be aware that you’re trying to salvage a $3 part. Per Etsy above $6 plus shipping gets you two used, non-functioning voice boxes.
Replacing the amplifying transistor requires de-soldering (which I find fiddly and tedious), then soldering in a new S8050 NPN transistor. That’s a common low-power transistor and is still available for a few dimes each in reasonable quantity. But I just happened to have a bag of (genuine Radio Shack) 2N2222 NPN transistors on hand, which should be close enough. So I soldered in a 2N2222 instead.
I don’t think I’d have done any of this if I didn’t already (plausibly) own the replacement part.
I’m not even going to count the things that may have gone wrong at this step, up to and including frying the new transistor as I soldered it in place.
In any case, I replaced it, and there was still no joy.
In hindsight, if you can’t fix it with batteries, or maybe batteries and a speaker (because the battery change frequently breaks the speaker wire), just chuck it. It’s a lot easier to buy in some used ones that only need a simple fix, than it is to figure out a complex fix on the one you happened to have.
Conclusion
Here’s what I found most interesting in all of this: Parts remain available. Sure, there’s some sort of unique chip in there that generates the voice. But most of the rest of the parts for this cheap-o 25-year-old voice box remain readily and cheaply available. Speaker, resistors, amplifying transistor, and so on. That’s a pleasant change from (e.g.) trying to fix a dead appliance, only to find that the required unique parts are no longer available.
Anyway, the final score is three for four. Of the four dead voice boxes I was given, one required only batteries, two required both batteries and a new speaker. The fourth one remains dead despite all attempts to fix it.
