All of a sudden my Ramps boards were not working.
When I checked I found some white patches present in between the pins. The same white patches available in A4988 also.
These boards were opened from a newly sealed packet only
What is the reason for this? How to clean this?
How to avoid this in the future?
it is hard to see in the pictures but you could try using some contact cleaner or IPA
I’m assuming it’s solder flux which was not properly removed.
I’ve seen this with really crappy solder flux lightly cleaned with isopropyl alcohol. It took some more alcohol, elbow grease and a PCB brush, but it came off.
It’s just solder flux that they didn’t bother to fully clean off. The header pins are usually hand soldered after the surface mounts parts are sent through the oven.
Just get some isopropyl alcohol, lightly soak a rag. Press on the surface flux to clean it off.
Let fully dry before powering it on.
Only way to avoid is to buy from reputable manufacturers like pololu.
Accually, waterdamage looks pretty much the same. But in any case, if you clean it with acetone, you should be good.
That can be solder paste residues or flux does not damage the circuit as it does not conduct the electric current but aesthetically severe ugly you can clean it with clean contacts or isopropyl alcohol
Thanks for your suggestions. Let me try with IPA
