Power supply board teardown

ATX / SMPS · 150 × 100 mm

Era read: Dominated by big electrolytics, transformers and heatsinks with few ICs. That silhouette is the low-grade tell.

Where the value sits

AC inlet & fuse

MOV, ceramic fuse, X/Y caps, NTC inrush thermistor. Silver electrodes, small amounts.

Bulk capacitors

200–450 V cans. Discharge through a resistor before touching anything else.

Main transformer

30–60 g of copper. The single biggest metal item on the board.

Heatsinks

Aluminium or copper. Weigh them in your hand — copper is 3× denser.

Rectifier bridge

Copper slug parts, no gold worth chasing.

Relay (if fitted)

On larger units a single silver-contact relay can beat the board's entire gold content.

Output wiring

Harness copper. Strip the connectors off.

Strip order

Value first, hazards first, heat last.

1. Discharge the bulk caps 1–10 kΩ, 5–20 W resistorsafety step

   30+ seconds, then confirm with a meter. Never short with a screwdriver — it welds the tip and can rupture the can. Aluminium electrolytic capacitors →

2. Cut the output harness Side cutters

   Insulated copper wire grade. Strip the connector shells. Insulated copper wire →

3. Pull the relay if there is one Hot air / pliers250–280 °C

   Crack the case, snip the silver rivets off the springs, keep them away from copper. Relays →

4. Pull the transformer and chokes Hot air + preheat380 °C

   Huge thermal mass. The copper is a third of the weight; the ferrite is worthless. Transformers, inductors, chokes & toroids →

5. Pull the heatsinks Unclip / unbolt

   Separate copper from aluminium and pull every steel screw out — one screw downgrades the lot. Clip-on and bolt-on board heatsinks →

6. Harvest the AC-inlet silver Side cutters

   MOVs, ceramic fuse, NTC. Only worth it if you're doing volume. Metal oxide varistors (MOVs) →

7. Sell the bare board —

   $0.60/lb. Don't ship this alone — freight will exceed the value. Low-grade boards (PSU, TV, modem, appliance) →

Other board types →