A home appliance PCB copy takes a physical control board out of a washer, fridge, oven, or air conditioner and turns it back into manufacturable files — Gerbers, a BOM with real part numbers, a drill file, and a schematic if you want one. You send the board, we measure and image it, and you get files you can hand to a fabricator. Most appliance boards are two-layer or four-layer, so this is one of the more predictable categories we handle.
Why appliance boards end up needing a copy
The reason is almost always the same, and it’s rarely about design theft. An appliance model sold for eight years, the contract manufacturer that made the control boards closed or moved on, and the original CAD files went with them. Now there’s a warranty tail and a spare-parts obligation, and nobody has anything but a bag of working boards.
The other common case is a single obsolete part. A triac, a specific opto-isolator, a mask-ROM display driver, or a proprietary motor pre-driver goes end-of-life. You don’t need a new design — you need the existing layout in editable form so you can drop in a replacement and re-spin one small area.
Third case: appliance service networks. A repair operation that supports twenty-year-old commercial laundry equipment can’t buy boards anymore. Rebuilding the board is often cheaper than replacing the whole machine, and the customer keeps the equipment running.
What actually happens to your appliance board in the lab
Here’s the working order for a typical appliance control board. It isn’t glamorous — it’s careful measurement.
- Incoming record. Both sides photographed under diffuse light before anything is touched, plus board outline measured with calipers, thickness measured, and mounting hole positions recorded against a datum corner. Connector positions matter enormously on appliance boards because the board has to drop into an existing plastic housing with a wire harness that isn’t changing.
- Component identification. Every marking read and logged — resistor and cap values, diode and transistor part codes, relay coil voltage and contact rating, triac and optocoupler types, the crystal frequency, and the electrolytic cap voltage and temperature rating. On appliance boards the electrolytics are usually 105 °C parts near the heat sink and 85 °C elsewhere, and getting that wrong on the copy is how you build a board that dies in year two.
- Desolder and scan. Components come off, the bare board gets cleaned and scanned at high resolution on both sides. Silkscreen and reference designators are captured before removal, because appliance silkscreens carry safety markings and creepage warnings you want to keep.
- Copper tracing and layer work. On a two-layer board, both copper layers are traced directly from the scans and cross-checked with continuity measurements. On a four-layer inverter or induction board, the inner layers have to be imaged separately — controlled sanding or chemical removal, one layer at a time, which is where the same layer separation work we do on industrial controller boards comes in.
- Netlist verification. The traced netlist is checked back against the original board with a meter, net by net, not just eyeballed against the scan. Ratio of found nets to expected nets is the honest quality metric here.
- Rebuild and DRC. Layout rebuilt in CAD with real footprints, then checked against IPC-2221 spacing rules — which matters more on appliance boards than almost anywhere else, because you have 120 V or 230 V mains on the same board as a 3.3 V MCU. Clearance and creepage slots on the original are copied deliberately, not accidentally.
- Copper current check. Heater, motor, and relay traces get a sanity check against IPC-2152 for the current they carry. If the original ran a 4 A load on a marginal trace, we’ll tell you rather than silently reproduce it.
- Prototype and compare. A small run gets fabricated and assembled, then compared side by side against your working board — supply rails, MCU clock, relay switching, triac gate drive, sensor readings.
The three appliance board types and how they differ
| Board type | Typical construction | What makes it tricky |
|---|---|---|
| Main control / timer board (washer, dishwasher, oven) | Single or two-layer FR-4, mixed through-hole and SMD, relays, triacs, mains section | Mains isolation slots, high-voltage clearances, relay footprint accuracy, conformal coating removal |
| Inverter / compressor drive (fridge, AC, front-load motor) | Two to four layers, heavy copper, IPM or discrete IGBT module, current shunts | Copper thickness measurement, shunt value and geometry, thermal pad and heat-sink alignment, gate drive routing |
| Display / touch / UI board | Two-layer rigid or FPC, capacitive pads, LED matrix, ribbon connector | Touch pad geometry must be copied dimensionally, not approximately; FPC stackup and stiffener placement |
Induction hob boards deserve a note of their own. They mix a high-current resonant tank, IGBTs on a big heat sink, and a small logic section, and the copper weight is often 2 oz or heavier. Measuring the actual copper thickness matters, because building it on 1 oz copper will look identical and run hot.
What you send us, and what you get back
Getting this right at the start saves a day or two of back-and-forth. For the initial feasibility check, before anything ships:
- Clear photos of both sides of the board on a dark, non-reflective background, whole board in frame, straight down, in focus. Phone camera is fine — good light matters more than megapixels.
- Board dimensions — length, width, and thickness. Rough caliper numbers are enough.
- The main chip marking, typed out exactly as printed, including the line below the part number. A close-up photo of the MCU and any custom or sanded ICs.
- One line on which deliverables you need — Gerbers only, Gerbers plus BOM, or full schematic as well. This single line changes the quote more than anything else.
- Whether the board is working, dead, or unknown, and whether you can send more than one unit.
From that we come back with three things: feasibility (yes, yes-with-caveats, or no and why), a lead time, and a price. Nothing gets started before you’ve seen all three.
On the return side, the standard package is Gerber files with the full layer set, drill and drill map files, an IPC-compatible netlist, a BOM with manufacturer part numbers and our notes on obsolete lines, pick-and-place data if you’re going to SMT assembly, and a fabrication drawing carrying the stackup, copper weight, surface finish, and solder mask color. Schematic capture, prototype build, and small-batch production are add-ons — the same deliverable structure described on our motor control board duplication page, since appliance inverter boards and standalone motor drives get handled the same way.
Where appliance PCB copy gets hard, and where it stops
This is the part most vendors skip. Some appliance boards are straightforward and some aren’t.
Conformal coating and potting. Dishwasher and washer boards are frequently coated, and outdoor AC units are sometimes potted. Coating comes off with the right solvent and patience. Fully potted modules are a different story — the epoxy has to be removed mechanically or chemically, and there is real risk of damaging traces and components while doing it. If your board is potted, send two if you have them.
Custom and house-marked ICs. Big appliance OEMs use custom-marked parts. A chip labeled with an internal code and nothing else may be a standard part underneath, and we can often identify it from pinout, package, and behavior. Sometimes it’s a genuine ASIC or mask-ROM part with no second source. In that case the layout can still be copied, but the board isn’t buildable without harvested or new-old-stock parts, and we’ll say so up front rather than after invoicing.
Programmed microcontrollers. A copied board is bare hardware. If the MCU on your appliance board holds the wash cycles, the defrost logic, or the temperature control loop, copying copper gets you nothing until the firmware is loaded. If you own the code, program it and you’re done. If the source is genuinely gone, firmware recovery from the locked part is a separate project with its own feasibility question — read protection on modern parts varies from readable to practically closed, and the answer depends on the exact part number and its protection level. We evaluate that case by case and never guarantee a specific device.
Fire-damaged or corroded boards. Boards from a burned relay or a flooded machine often have missing copper. If a trace has vaporized, it has to be inferred from the circuit’s function — doable, but it’s engineering judgment rather than measurement, and we flag every inferred net in the deliverables.
Safety compliance. Reproducing a board’s copper does not reproduce its safety approval. Appliance boards with mains circuits sit under agency-listed constructions. If you’re producing service spares for equipment you own or support, that’s usually a manageable path. If you’re putting boards into new product, budget for testing.
What drives the price on an appliance control board
No number here, because a two-layer oven timer and a four-layer inverter drive with an IPM are not the same job. What moves the figure:
- Layer count. Two layers is straightforward. Four layers means destructive layer separation and roughly doubles the tracing work.
- Component count and mix. A hundred parts costs more to identify and enter than thirty. Unmarked or house-coded parts cost investigation time.
- Deliverable set. Gerbers plus BOM is the base. A verified schematic is a real increment because it means understanding the circuit, not just reproducing it.
- Coating, potting, or damage. Anything that has to be removed or reconstructed adds hours.
- Firmware involvement. Priced separately, always, and only after feasibility on the specific part.