DOLBY IMS 2000 Stuck ingest progress that can not be deleted or canceled

[Fraser Falconer]

Hi Harold,
Yep, I have had that very same issue with flux and SMT chips. I'll find a sample of the issue with the glue on an old PCB and post for all to see.

Cheers Fraser

[Mark Gulbrandsen]

In 50 plus years in electronics I never had any flux issues of any sort in equipment. I had the usual amount of bad/cold solder joints and I did have lots of problems with equipment that used dissimilar metals such as power transistor pins coming un-soldered from circuit board traces over time in BGW amplifiers, and pcb feed through rivets back when I was a tech at Panasonic. But dissimilar metals are never friendly to a solder joint.

[Steve Guttag]

I think it is all in how well the boards were cleaned from the flux. I also suspect that the types of boards Harold is referring to has a very tight density of components where the presence of flux could create a path between components. Overall though, I really haven't had solder/flux related issues in my career either...including a lot of Heathkits built from some time ago...many of which are still running to this day...but that stuff was, by and large, very low density components with non-sensitive timing issues. Lately, I've had more problems with IC socket failure on a clock.

[Bruce Cloutier]

At this point we are using a no-clean flux and the amount of residue on the board does vary a bit. But, we run using a selective solder system and the flux is sprayed only where solder is needed. That is basically thru-hole pins for connectors. Add to this that our designs do not place components on the solder side. So I am not expecting troubles from flux. We are not also gluing anything but glue degrading into a conductive material is an interesting issue. We aren't also doing audio or video circuitry where leakage might be more of an issue.

In the mid-2000s when we were using a contract manufacturer (CM) who washed our boards, we did have an issue with flux under a clock crystal. This would prevent the clock from running. We had to remove the crystal, clean the board and replace the part with a new one. I personally did most of that rework. We had a lot of issues with that CM though and we had to move on.