Alex0607

So my E60 started showing up PDC failure symptoms about a couple of months ago. I checked the sensor and found 2 sensors not emitting any clicks. So I decided to replace the sensor and ordered some online. Cheapo type from China. So today I decided to install the sensors all to the front and guess what. None of the sensors are working now. Even the new ones. I went online and found some links describing issues with the module at the back. I took it out, pried the box open and this is what I see on the circuit board. I guess those SMD are fried.

Can I call this one dead?

seanjordan20

Clean them up with some alcohol and test them with a multimeter. If bad they are not too hard to replace

habbyguy

I agree - I've cleaned a lot of boards that looked worse than that. The good news is that the damage seems to be contained to the area of discrete components, and not to the chips with the tightly-spaced connections. You may well get lucky with this one... certainly worth a shot.

scottalexander

How do you think the board got damaged?

habbyguy

Water

alex.baker89

Yeah +1 on water damage. As people have already said, clean up with isopropyl alcohol and test the traces for continuity with a multimeter. It also can't hurt to check for any dry solder joints and reflow them if you find any, seeing as you're already in there. If for any reason you do need to replace SMDs, I wouldn't agree that it's a complete walk in the park. If you have a hot air station it might be a bit easier, but with a traditional solder station it's a bit fiddly. If you do need to go down that road, I'd advise a decent tabletop magnifier and a good selection of different sized tweezers to make the job easier.

To prevent any future water ingress it might be a good idea to consider using a bit of insulation tape around the gaps in the casing when you're putting it back together, just for extra peace of mind.

Edit: in the bottom left hand corner where you've circled, is it me or does it look like an IC and 2 resistors are missing?