Found a PDF of a dentist's chair manual from 1987, buttons do the opposite of what you'd think

So I was digging for a part number for an old Adec unit and stumbled on this scanned manual from 1987. The emergency stop button is labeled with a green arrow pointing up, but it actually lowers the chair into the floor position. I clicked through a few pages and the wiring diagram has two wires crossed that they never fixed in the text. Nearly followed it to trouble a brand new chair last Tuesday and caught myself right before. Has anyone else run into old equipment docs that are just flat wrong, or am I the only one dumb enough to trust a 37 year old PDF?

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hayden_rodriguez2d ago

Actually, 37 years is nothing for dental equipment. My office still runs a chair from 1985 and the manual says the foot pedal does the opposite of what it does, but honestly that old thing has outlived three newer chairs (you know, the fancy ones with screens). The real issue here is you assuming old docs were ever right. Those 1987 manuals were written by guys who had never touched the chair, they just copied the spec sheet and moved on. And the crossed wires thing, that's probably a printing error that every tech since has just worked around, so the safe bet is to test everything yourself before touching anything. You're not dumb for trusting it, you're just new to the game.