Rising Damp

Photo of water damaged board from Pitagora
A reader contacted me with this tale of woe … and not related to dodgy landlords stereotyped by Leonard Rossiter’s character Rupert Rigsby. He had a problem with his Mundaneo (his description). We’d conversed a couple of times before and he told me this story.

The Mondeo has been giving me grief recently - would not run on LPG, really bad miss-fire, running rich.
I went through all sorts, plugs, HT leads, coil pack, Lambda probe, even changed the vapouriser! Eventually I put a frequency meter on the pins of the Pitagora and found that the injectors were still running when I was supposed to be on LPG!

Quick swap of the Pitagora and everything a-ok!

(I opened up the old one, it's obviously spent some time badly mounted as one corner of the PCB is corroded....)

Underside of damaged Pitagora board
You can see the result of the water damage here. It certainly looks like some intellectually challenged person had mounted it so that water could get in and stay in. Actually, “mount” is a bit of an exaggeration, the so called “professional” installer had simply tucked it behind the suspension turret !

Once water gets in, unless it is pure de-ionised water, then electrolytic corrosion will occur and the tracks of the PCB will get slowly eaten away. I lost the original radio in the Disco to that - the back of the radio sits in a depression in the top of the tunnel, and when the heater matrix leaked, it filled the depression with water and after a while the radio stopped working.