The controller board has been inspected and cleaned. Restored communication and thruster operation have not been confirmed. A cleaner board is progress, but it is not yet a repaired controller.
The symptom
The control panel reported PPC820 STERN / Error 12 / No Communication. The bow PPC820 appeared in the device list and the bow thruster operated normally. The stern controller remained absent.
That gave me a useful comparison: two related systems aboard the same boat, with one responding and one not. I started by documenting power, fuses, cables, and the network before opening the controller.
What I tested
The stern battery measured 13.37 V, and both small fuses tested good. Substituting the working bow S-Link spur cable did not change the fault. I also disconnected both wireless remote modules and reset power; the stern controller still did not communicate.
| Observation | Recorded result |
|---|---|
| Stern battery | 13.37 V |
| Small fuses | Both tested good |
| Known-working spur cable | No change to the communication fault |
| Wireless modules removed; power reset | Stern controller still absent |
| Measured CAN pair, stern | 58.8 Ω |
| Same pair, flybridge | 58.5 Ω |
The resistance readings were similar at the two test points. Powered measurements were also recorded for comparison with the bow controller. Those observations supported further investigation of the controller, but they did not prove that valid CAN messages were reaching it.
I am keeping these as measurements from this particular investigation. I have not established an official connector pinout in this article.
Inside the controller
Inspection revealed localized corrosion in the low-voltage control-board area, around small components and their connections. Microscope photographs made the affected pads and component leads much easier to examine. The microscope didn’t fix the problem, but it certainly made it bigger.
I asked about supported repair options. The manufacturer’s support route was a complete replacement controller rather than a separately supplied control board. An independent repair shop offered an evaluation, giving me another possible route if the initial cleaning does not restore communication.
Cleaning and inspection
With the board de-energized, I worked through several conservative cleaning passes using 99% isopropyl alcohol and a soft electronics brush. Fresh alcohol flushing helped remove loosened contamination.
The later microscope views exposed the component bodies, leads, pads, and traces substantially better. I did not identify an obviously missing component or a completely severed visible trace in the photographs. Some dark, pitted, or discolored metal remained at component terminations.
I stopped further aggressive cleaning rather than risk disturbing weakened pads or components. Loose corrosion on some enclosure screws is a separate issue to address while checking the case and gasket for a possible moisture-entry path.
Costs, options & sourcing
The important comparison is between repairing the existing control board and replacing the complete controller. These are the businesses I contacted and the answers I received.
| Source / option | Quoted cost | What the offer means |
|---|---|---|
| Imtra Reconditioned SMPPC820R | $1,218.75 + $100.55 tariff $1,319.30 before tax and shipping | September 28, 2026. A complete replacement controller; support confirmed it as a direct replacement for my PPC820 and quoted a two-year warranty. This is my case-specific offer, not a current catalog price. |
| PCB Tech USA Component-level repair | $650 if repaired, plus shipping | September 28, 2026. Offered an initial inspection at no charge and a discussion of the findings before paid work. Will inspect without a schematic; hidden corrosion or damaged traces could make repair impractical. No successful repair is guaranteed. |
| Garner Co Another board-repair candidate | Free diagnosis offered; repair price not yet quoted | October 1, 2026. Will evaluate corrosion damage and attempt component-level repair without a schematic. An invitation to inspect is not a completed diagnosis or a firm repair price. |
| ACS Industrial Services | No quote | September 28, 2026. Doubted that repair would be economical. That was a response to my inquiry, not a failed bench repair. |
The PCB Tech offer is $669.30 below the quoted replacement price before comparing shipping, taxes, time, and the chance of an unsuccessful repair. That makes an evaluation worth considering; it does not establish a guaranteed saving.
My current approach is to finish the cleaning-and-test stage, then obtain a professional board evaluation if communication is still absent. The reconditioned Imtra controller is the fallback. Garner’s reply adds another shop to check before committing.
Sources: support and repair-shop emails dated September 28 and October 1, 2026. These historical quotes apply to my unit. Confirm a shop’s current diagnostic fees, repair terms, shipping, and warranty before sending equipment.
What I have spent so far
| Item | Recorded order total |
|---|---|
| Elikliv 4.3-inch digital microscope | $42.79 |
| Rechargeable electric air duster | $25.67 |
| Five-piece ESD electronics brush kit | $7.48 |
| Documented purchases | $75.94 |
These are the actual recorded order totals, rather than today’s advertised prices. The tools are reusable, but I am showing their full purchase cost here because this investigation prompted the purchases. The first microscope order was canceled without a charge and is excluded.
No professional repair or replacement purchase is recorded yet. Alcohol already used, other incidental supplies, and my time have not been separately priced. $75.94 is documented spending so far, not a final all-in repair cost.
The next test
The next milestone is a communication test after the board has dried thoroughly and the controller is ready for appropriate reassembly. The question is simple: does PPC820 STERN reappear in the controller information, and does the communication error clear?
If it remains absent, the plan is professional board evaluation before deciding on a replacement controller. Successful enumeration would be an encouraging first result; operational verification would still follow.
Lessons so far
- A working related system can provide useful comparisons while troubleshooting.
- Document each isolation test and whether a power reset was included.
- Similar network measurements do not establish that the devices are communicating correctly.
- Take photographs before cleaning. They preserve details that may help a repair technician later.
- Keep the distinction between an observed fault, a suspected cause, and a confirmed repair.
This project remains open. I will update this page when the next test establishes something new.
I keep the detailed private record for this project in NautiFile, the boat-records app I’m building for equipment, service history, documents, photos, and expenses. Read the story behind NautiFile.
Loading comments…