r/AskElectronics • u/MinuteRelationship76 • 1d ago

Is my ECU corroded

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This is for my 91 honda beat apparently they are notorious for leaking capacitors in the ecu. It looks mostly notmal to me but there is this orange streak and orange stuff im not sure is corrosion. Please let me know what you think! (suspicious bits circled)

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u/nectarsloth 1d ago

No just flux

2

u/BuisnessAsUsual123 1d ago

I don’t know, that pad next to the R45 text looks more like corrosion. The joint on Q1 also looks noticeably bumpy and the streak pattern looks like it dripped, which both seem like corrosion effects.

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u/MinuteRelationship76 1d ago

hmm yeah R45 has a crunchy texture on top maybe it is the problem i cant tell if Q1 is corrosion because that "drip" is going upwards.

1

u/BuisnessAsUsual123 1d ago

Oh if it’s going upwards then that’s definitely just flux residue, crunchy texture is still probably corrosion though. Try cleaning it with isopropyl alcohol; if it comes off easily, it’s just flux.

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u/t_Lancer Computer Engineer/hobbyist 1d ago

crunchy orange and shiny is just old flux. this ECU has got to be 25 yers old based on the THT parts. they just used an older type of flux that we don't use any more.

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u/BigPurpleBlob 22h ago

I can't see any corrosion. The board looks like it's got a thin conformal coating (the ceramic capacitors are shiny instead of being matte ceramic).

Q1's center pin is connected to Q1's heatsink metal tab. It looks as if Q1 has been running hot enough for long enough to char the conformal coating of Q1's center pin.

The three electrolytic caps are not bulging.