A reader has suggested an explanation to my question. It seems a reasonable explanation and others do agree with him. But that is not likely to be the correct explanation for two reasons as I explain in this update.
“A picture is worth a thousand words.”
Here is an early picture of PT/35(b)
Here is another one.
According to our timeline, Picture 334 was taken on or before 22 Sept 89.
22 September 1989
Photos 333 and 334 of RARDE report – close up photos of fragment, were taken on or before 22 Sept 89, according to the photographic register (FC3877 and FC3878).
And now, let us take a look at a picture taken at a later time. (27/04/1990)
Just to be sure, look at this one too.
And this one.
(I really like this one!)
The early pictures show that the left bottom part of the “1” shaped pad has a clean and straight edge. The latter pictures show that some “TIN” has flown over the edge of the pad.
How do you explain this?
ANSWER from a reader (Comment from Brendan)
That silver bit sticking out of the bottom left of the “1” pad appears to line up with the contours of an area of solder on the pad. That area of solder (which presumably had been applied to connect one of the pins of the relay) looks flatter in the photos taken after the other corner was cut from the board fragment. That smooth surface can be seen in these images too:
In the photos from before the cutting, that surface looks less uniform (see Picture 334, the second image in the article above). The same kind of uneven structure can be seen in the top right part of the “1” where a wire was apparently soldered on.That looks like a mountain shape in the last picture above.
So it’s possible that whatever flattened the surface area also pushed out some of the solder from the pad onto the bare part of the board.
The only thing that I can think of that would cause that is something like a vice grips that could have been used to secure the fragment while the bottom right hand corner was being sawed off.
It’s possible that the heat of the saw cutting through fibreglass caused the solder to melt while the board was being gripped. However, the solder could have been flattened simply by being gripped extremely tightly. Without a very secure grip, the fragment could have cracked as a result of the sawing action. Whoever cut the board may have set the grip extremely tight to make sure that far greater destruction of the board would be avoided.
Here is a picture taken BEFORE “the bottom right hand corner was being sawed off.” The solder “out of the pad” is already visible.
Also, here is another question: Why is there any soldering at all on that part of the pad? The wire was (according to the investigation) soldered on the top part of the pad. And the relay is NOT soldered to this (bottom) part of the pad either!
Here is a larger view of the pad.
So? Any idea?