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MICROSCRAPPINGE-waste field guide

⚡ Stored high voltage

fatal

Where you meet it: CRTs · microwave oven HV capacitors · PSU bulk capacitors · flyback transformers · any large oil-filled or motor-run capacitor

What you need to know

A CRT holds 25–30 kV on the anode and recharges itself through dielectric absorption after you discharge it. Discharge through a series resistor to the dag ground, repeat, then leave a shorting strap in place while you work.
Microwave oven HV capacitors can deliver a lethal shock months after unplugging. Discharge before touching anything in the cavity.
PSU bulk caps (the big 200–450 V cans) likewise. Use a 1–10 kΩ, 5–20 W resistor across the terminals for 30+ seconds, then confirm with a meter.
Work one-handed, other hand in your pocket, around anything undischarged — it keeps current from crossing your chest.
Isolate and lock out. Never work on plugged-in equipment.

The rule: NEVER short a large capacitor with a screwdriver. It welds the tip, blasts molten metal at your face, and can rupture the can.

Components this applies to

Silver-Graphite Brushes & Slip Rings Contacts & relays · $150–400/lb Ag 40–95% by weightCu pigtail + commutator segmentsBase electrographite S Thermostats, Snap Discs & Limit Switches Contacts & relays · $25–120/lb Ag 0.4–1.6 g/lb as whole discs; 408–431 g/lb as harvested contactsBase bimetal steel discBase Hg ~3–4 g per bulb thermostat ampoule B Arcade PCBs / JAMMA Boards Boards · $30–800/lb Au 0.05–0.20 g per board ≈ 0.09 g/lbCu ~45 g/lbAu ceramic gold-lid customs (FD1094 C Automotive relays & fuse boxes Automotive · $3–10/lb Ag 25–80 mg per mini ISO relayCu 1–3 g coil + terminals per relay C Automotive wiring harness Automotive · $1.5–3/lb Cu 48–52% recovery stripped; ~35% as-pulledAu under 0.1 g per whole vehicle C DC-DC converter bricks & isolation modules Other · $40–400/lb Au 0.08–0.3 g/lbAg 1–4 g/lbCu ~90 g/lb C Enterprise Switches, Line Cards & Optics Boards · $3–200/lb Au 0.15–0.6 g per large line card ≈ 0.075 g/lbCu ~70 g/lbBase chassis backplane C EV / hybrid battery management boards Automotive · $5–15/lb Au 0.01–0.05 g per master boardAg ~0.1 g per master boardCu 10–50 g busbar traces per cell-tap board C Hybrid / EV traction inverter ⚡ Automotive · $8–20/lb Cu 3–8 kg per inverterAg 0.5–3 g sinter per power stageAu 0.02–0.08 g on gate-driver boardsBase 5–15 kg aluminium housing C Instrument clusters & head units Automotive · $3–12/lb Au 0.008–0.100 g per unitAg 0.2–0.6 g in a premium head unitPd 0.02–0.06 g in a premium head unitCu 20–500 g C Klystrons & Travelling-Wave Tubes RF, power & vintage · $3–40/lb Cu ~250 g/lb (0.35–0.75 lb Cu per lb of tube)Au ~0.5–4 g per tubeAg 2–30 g per tube C Metal oxide varistors (MOVs) Other · $15–40/lb Ag 6–14 g/lb C Xenon HID ballasts & LED drivers Automotive · $2–6/lb Au 0.003–0.015 g per ballastCu 30–90 g in the HV transformer and inductorsAg trace in thick-film and solder C Aluminium electrolytic capacitors Capacitors · $0.3–1/lb Base aluminium can D CRT flyback transformers & deflection yokes ☠ RF, power & vintage · $0.5–1.5/lb Cu 150–400 g per yokeBase ferrite core D Laser Printer Boards, Fusers & Toner Chips Boards · $10–60/lb Au 0.01–0.04 g per formatter board ≈ 0.045 g/lbAu 0.0005–0.002 g per toner CRUM chip ≈ 0.3–0.8 g/lb of chipsBase Fuser: no precious metal whatsoever D LCD Panels (ITO / CCFL vs LED) Other · $0–8/lb Base Indium ~0.4–0.8 g/m² of ITO layerAu 0.01–0.08 g per panel in COF tape bumpsCu ~17 g/lb D Low-grade boards (PSU, TV, modem, appliance) Boards · $2–4/lb Au 0.005–0.05 g/lbAg 0.2–0.8 g/lbCu 8–15% D Magnetron ☣☣ RF, power & vintage · $1–4/lb Ag 0.5–2 g per magnetronCu 200–400 g per unitBase ferrite magnets D Nixie Tubes, VFDs & Dekatrons Other · $150–900/lb Base nickel cathodesBase tungsten filament (µg) in VFDsBase total metal value $0.02–0.15 per tube D Photomultiplier Tubes (PMTs) Other · $150–900/lb Ag 0.1–2 g per tubeAu 0–20 mg per tubeBase BeCu dynodes with an activated BeO surface D Power supplies Other · $1–2/lb Au 0.005–0.03 g/lbCu 30–60 g per transformerAg in the relay D Spark plugs Automotive · $0.5–2/lb Pt 1–8 mg per plugBase iridium 0.6–3 mg on Ir plugs D Vintage Home Computers & Boards Boards · $80–350/lb Au 0.05–0.20 g per C64 board; 0.1–0.4 g per Apple II boardAu gold-lid ceramic DIPs at $150–400/lbCu ~40 g/lb D

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