mobythevan Posted December 13, 2006 Share Posted December 13, 2006 Out of the 5 megasquirt installs we did last year there was one that never functioned correctly (Chris's car), some of you probably remember the description. Resets all the time in the beginning, tried several noise filters at alternator, by MS, by coil, etc. Tried not hooking up alternator. All the usual stuff that everyone sees and tries with reset problems. In the end it seemed like moving the MS box helped some. Well, here is what my friend (Mike) found yesterday.... Mike took back the suspect MS box and decided to check it for cracked solder joints, because the history of the resets shows that they come and go with no reason. Sometimes Chris can drive the car for months with no problem (it is his daily driver), other times it resets several times in one day. When Mike popped open the case last night he found the processor was not plugged into the socket, one whole side was hanging out and just barely making contact enough to work sometimes. We are sure that the processor has been in this state every since the unit was built (built by Mike, not DIY or anyone like that). Anyway we are waiting for the updates now, but it may take several months to verify no resets every happen again. If they do, the next thing we are going to do is re-flow all solder joints, because it was soldered by him and was his first solder job. The processor not being seated in the socket correctly seems to be the cause of this one, you guys also be careful that one or two pins don't bend under the processor when it is seated, I have seen that before. At this time the only conclusion I can draw is that the other 4 units I built work fine to this day, I have had professional instruction with soldering and have been doing it for 10 years in my various hobbies. The one unit that Mike assembled is suffering reset problems. I guess the moral of the story is to have DIY or someone else build your MS unit if you are not sure you can do a good job soldering and assembling the other parts of the unit, seating the processor These resetting problems are so frustrating that it is not worth saving the money to assemble yourself. Quote Link to comment Share on other sites More sharing options...
big-phil Posted December 13, 2006 Share Posted December 13, 2006 Thats why I got one that was put together already. I wanted it done right. Quote Link to comment Share on other sites More sharing options...
z-ya Posted December 13, 2006 Share Posted December 13, 2006 A good visual inspection can save hours of debug. Any DIP package that plugs onto a socket should be visually inspected. Pins can get bent underneath the package, and cause intermittent connections. Hold the board on edge up to the light, and you should be able to see them. Also, you should always inspect all solder joints, even if you purchased it assembled. I've found cracked solder joints on pre-assembled units. What causes cracked solder joints? Wrong solder-temperature profile. Each solder formulation requires a certain heat range. If the heat range is wrong, as the solder cools, it can crack. Or if the solder is overheated, it can also crak when it cools. Mechanical flexing also can cause cracks. Quote Link to comment Share on other sites More sharing options...
randy 77zt Posted December 14, 2006 Share Posted December 14, 2006 i bought my ms/relay board/stim combo from diy.no problem on the ms but i think the relay board might have a cold solder joint-it wont fire the fuel pump unless you slightly wiggle the relay. Quote Link to comment Share on other sites More sharing options...
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