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I've seen a couple of posts where information has been presented on how to repair broken or blown traces on the ECU PCB. Here a a couple of recent examples:

sicknastyb17:

I like to fix the traces using dish soap and a razor blade to carefully remove the green coating on the board to expose the broken trace. After exposing the trace carefully clean the trace using brake cleaner and a toothbrush. Make sure the brake cleaner is alcohol based and NOT water based (Autozone is alcohol based) Then use a silver trace pen to fix the broken trace. (radio shack $10) This work great. BTW the silver trace pen does not create resistance free trace until it is fully dried.

scanikwwo:

I use yellow kynar and then i always put some green nail enamel on this repaired area. Looks almost like it was designed that way

Personally, I've tried using the silver trace pen and haven't gotten "optimum" results but I'm probably doing something wrong (sicknasty, can you elaborate?).

The purpose of this post is to share information on repairing the boards the "correct" way. Thanks in advance to those who contribute!

Well remember that the silver trace pen will not leave a good trace until it is fully dried. Second remember to shake the pen ALOT before trying to use it. As for that this is the way I have reparied all the ecu that have trace issues. Hope this helps

Thanks for the input. I see you live in the same town as PGMFI's "founder", Blundar. Bet it's an advantage having him near you

Dave is a very busy man. But It has helped from time to time.

If it's straight part you can just peel the isolation of the kynar, then use a razor blade to remove the soldermask from the pcb, heat the trace, and solder the bare wire onto the broken trace. I ude this method if i see, that it can be done clean. If i'm not sure where the damage is i just get the wire and put it straight from one pad to another. Trying to lay it on the factory trace of course Get yourself a nice green enamel to make it look sweet and clean as it was factory made. Thin coating does the job usually. If it's more complicated, and the damage is on both sides i always use wire to go through the vias in the pcb to rebuild the lost connection. If the pads are gone i reconnect the bootom layer with upper by leaving extra 0,5cm of wire at the top and i spin this around the legs of this particular part to make a good and strong connection.

Excellent advice - thanks Scan!

Ok, how about cleaning up PCB's with cap leakage?

I like to remove the caps and surrounding components. Then I use a toothbrush to get the surface gunk off. I then clean the area with a toothbrush dipped in alcohol and let it dry. I'll dry the area manually then I lightly scrape the affected area with a thin fine tipped screwdriver which removes any gunk still stuck to the PCB before installing new caps and reinstalling the other working components after testing them to make sure they weren't damaged also.

I didn't read this anywhere - I developed it over time and it has worked well and allowed me to offer a warranty on my repairs. I am open to suggestions/criticisms and even solicite them so that I may improve my skills. One area I'm concerned about is leaving the repaired area exposed after removing the light coating on the original board. Is there a product I can spray on it after repairing and replacing the components that will restore the coating?

Raul

To clean the surface after a cap has blown i use cotton buds dipped in isopropanol. I always remove the surrounding dirty elements and clean them so they doesn't look like after world war 2.

To make a nice protective coating i dip some alcohol into solid flux (in these little metal cans) and then wait for the alcohol to react. I apply quite fat layer so it looks like stock. It shines now like charm. You can even use spray can with clear paint, but its a pain in the as* if something goes wrong. It is not that easy to remove as my first method.

Hope this helps

Just a piece of wire from one pad of the blown trace to the other is what I would do.

It's a good solid fix that no-one sees on an ECU anyway.

I see it

They do if your reselling the ecu.
I clean spots on the pcb after caps leak using Autozone brake cleaner with a toothbrush. This works great on pcb's. Only autozone (again because its alcohol based and NOT water based. Its a great all around pbc cleaner, just dont get it in the pa sensor

SickN, do you lower your price for repaired ECU's? I've taken off up to $50 sometimes on Ebay, just because it has been repaired but maybe I'm taking off too much...

I don't on ebay. I only sell ecus that have all original traces on ebay. Now if I have to replace injector drivers or voltage regulators will not state the fact that this work was done to the ecu. As for replaced traces I will only sell those at my own shop along with non repaired ecus. I make sure to state the ecus has been repaired and sell them at about 30-40 bucks off.

If an ECU has been repaired, I'd rather see where the repair was, as it would be the first thing I'd look at if the problem re-curred . . .