So apparently in 1993, Avon (the MLM (not that MLM (or that kind either))) commissioned a Soft Foam Telephone.
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Inside the plastic, we've got a single-sided PCB with a single IC and a bunch of discrete (and discreet!) components.
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The IC is an HM9102D. That's a Hualon Microelectronics TONE/PULSE SWITCHABLE DIALER WITH REDIAL
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@foone Can you rebuild it? 🫣
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So the way this thing is broken is odd: You plug it in, and you can turn it on (yeah this landline has an on/off switch, which is itself weird) and the LED comes on, but that's it. You CAN hear it clicking when you pulse-dial, but nothing otherwise
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This thing was definitely hand-soldered. With one possible exception they look fine, though.
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@eaterofsnacks I'm hoping so!
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Nope, there's no bridge here. I checked.
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R [email protected] shared this topic
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@foone on/off for the ringer, probably
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Annoyingly there's two version of the datasheets: a 1-pager that just gives the specs, and a 5-page one that talks about circuits and such.
the 5-page one is only available in chinese and when I attempted to translate it, google just gave me punctuation.
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no really. it only included the punctuation.
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Testing in circuit, I'm seeing 2.1v across VSS/VDD on that chip.
The nominal voltage seems to be 2.5v? so that might be a problem -
@foone "significant white space and punctuation" kind of language
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hmm. no, if this translated electrical characteristics table is at all correct, it should be fine down to 2v. So we're close, but not dangerously low.
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this thing has a bunch of little caps and diodes and transistors. I've visually inspected it but I don't see any issues with any of them.
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Infoseepage #StopGazaGenocidereplied to Foone🏳️⚧️ last edited by
@foone This is like one of those old school restricted writing challenges! Write a novel without using the letter e! Seems like the perfect thing for a LLM, except they can't count letters and will tell you that the color of the sky is fish.
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I'm getting the expected -51V on the input, so there's no problem with the cord or the PBX powering this
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and the fuse is fine, I did test that.
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Here's the translated(ish) schematic from the HM9102D datasheet.
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I'm gonna assume this device is basically this design with with minimal changes.
