EuroDat said:

On a different note: We have a couple of old process plants using old ABB Bailey Network 90 control systems. The parts are NLA and good spares are hard to find. We were having problems with drift. We had spares, so we vacuumed all the dust off and decided to clean them with ultra purified water. Literally dropped them in a bucket of water and then dried them in an oven for 8 hrs at 50degC. They have never worked better.

The dust gets in and changes the resistance which causes drift. "Washing" them solved this problem. I have done this on mobile phones. My sons phone has been through the washing machine twice and this saved it.

If I had a spare ECU, I would consider trying it. Even though it has worked on 16 of these ABB units without fail, I am still reluctant to try it on my ECU. Just cant get use to the idea of dropping it in water.

Interesting! I might have to try that! As I recall, there's nothing on the boards that would be damaged by water or alcohol.

As a matter of fact, way back when at the factory, they probably were cleaned with water or alcohol after soldering. Back then? Probably alcohol.

Just make sure they're thoroughly dry after cleaning before you put power on anything. (And I would not recommend compressed air to speed the drying process...)

Oh, and Yes... There are some high impedance points in the ECU design... Like MegOhms high.

So it's perfectly conceivable that dust and/or other contaminants which have accumulated in these areas over the years could slightly affect operation. :bulb:

  FastWoman said:

Interesting! I might have to try that! As I recall, there's nothing on the boards that would be damaged by water or alcohol.

My first "real" job was in the 70's with the Xerox Corp., in a copier refurbishing center. We would disassemble equipement and place circuit boards and other components on rolling baker racks into a booth, where they would be sprayed with high-pressure wands- just like a self-serve car wash- to remove toner, dust oils, etc.

Hot water, hot soapy water, rinsed, blow-dry and then sprayed with MEK to removed any toner that had bonded to the boards. Blow-dry and staged for testing and re-use.

I'm going to read through the 2 articles from Willoughby today sometime. I felt like 12 was a decent number of teeth but not excessive....it's less than 1/4 turn of the wheel but I'm sure it makes a large difference weight wise.