2014-07-17 1:40 GMT-03:00 Erik Christiansen <dva...@internode.on.net>:
> Leonardo, one other thing worth checking as you go is all the solder > joints. A "dry joint" occurs if a component being soldered moves > slightly during the brief period when the solder alloy is pasty, > i.e. neither liquid nor fully solid. A fraction too little heat into the > joint is sometimes a factor, e.g. on heavy leads on a large component > amongst many fine components on a flow-soldered PCB. Such joints may > work fine for years, then fail in an intermittent fashion. > > I remember encountering one which coincidentally was on a large > electrolytic capacitor. After years of use, I was able to pull the > component lead out of the joint by hand. That is unusual, as dry joints > normally appear solid, but rough¹ around the component lead. (In that > case, the lead may have become lightly oxidised during storage. Who > knows. I scraped it to bright metal before resoldering.) > > If the unit is old, then replacing the electrolytics is a sound > investment in reliability. If that doesn't fix the problem, then > resoldering the other joints on the PCB _may_ do the trick. > After that, troubleshooting becomes trickier. > > Erik > > ¹ Or, if unbelievably bad, the molten solder has not wetted the lead or > solder pad. Instead of flowing out over it, the solder sits in a blob, > barely making contact. That's more likely in inexperienced hand > soldering. > Well, the big capacitors are screwed, but there are other caps and resistors that are not mounted on the pcb but have terminals, I guess that's worth checking. From what I could see there's one big PCB only, full of components. I will have to remove it to check it if all the other components that are not soldered are ok. If anything of these things don't work I will have to replace the drive for another. I'm even thinking about setting the spindle motor to a fixed speed with contactors as I repair or buy another drive. The only thing I'm scary about this is, how much time it will take to identify all the signals and make it work. I have the schematics and thankfully they show the input and output pins but there's no description of any signal. For example, the tachometer that senses the spindle RPM outputs to the Fanuc spindle drive, and then from there, there are several pins that output to the NC to tell the spindle speed, and if there is a fault condition. I guess I will have to work in reverse engineering to know how the signals work, because now with the alarm I can't even move the joints. -- *Leonardo Marsaglia*. ------------------------------------------------------------------------------ Want fast and easy access to all the code in your enterprise? Index and search up to 200,000 lines of code with a free copy of Black Duck Code Sight - the same software that powers the world's largest code search on Ohloh, the Black Duck Open Hub! Try it now. http://p.sf.net/sfu/bds _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
