Author Topic: Repair Lifted Trace on GAC Speed Controller ESD-5111  (Read 113 times)

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Offline dr00bie

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Repair Lifted Trace on GAC Speed Controller ESD-5111
« on: July 30, 2020, 03:00:04 am »
A friend asked me to look at a faulty PCB from a piece of equipment that he uses for his business. He has been unable to find a replacement of the exact part. If you know of someone who might have a replacement, he is very interested in buying one if this cannot be fixed.

The board is a Governors America Corp (GCA) ESD5551 Speed Controller and is used for a surplus US military generator. My searches for a schematic have been fruitless, the document I found for the ESD5550 series doesn't show the same part as this one.

I opened the case and found that the board was coated in a very thick, soft conformal coating. Initial inspection showed that the coating had lifted and separated from one section of the bottom of the PCB. It appeared that the solder mask was damaged and part of the trace was darkened. I carefully removed the coating with a nylon spudger and the coating lifted almost all of the rest of the solder mask from the trace and actually lifted a large portion of the trace foil as well.

The trace goes from one leg of a large resistor (unknown value at this time, have not desoldered yet) to 5 pins of a 54 pin Molex connector. The trace is complete as it goes under the connector, so I am unsure what the best fix would be.

1) Remove the lifted foil and scrape the PCB and put in a copper jumper from the connector to the through hole pad.
2) Superglue the lifted foil down, scrape and install copper jumper into damaged section where no foil is present.
3) Something else?

I have attached 4 images,

1) Bottom: Showing lifted trace after coating was removed and affected pins on connector.
2) Top: Top of board showing the affected pins on the solder-side of connector. At far left, you can see part of the resistor that is mentioned above.
3) Conformal_connector: Initial view of conformal coating and connector.
4) Conformal_Close: Closeup of initial view of conformal coating.

« Last Edit: July 30, 2020, 03:05:09 am by dr00bie »

Offline SMdude

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  • Country: au
Re: Repair Lifted Trace on GAC Speed Controller ESD-5111
« Reply #1 on: July 30, 2020, 01:24:23 pm »
What does that trace hook up to off board? Something has shorted out for the trace to burn like that.
As for the trace itself, I would probably just spray some conformal coating on it and keep it pressed to the board while the coating dries.

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