I have now finished the control board as well. All resistance checks passed. I can not do the LED test, because I do not have the diode tester here, it’s in LMX. In any case, I have been very careful when mounting the LEDs, so they should be all right.
The warning in the assembly manual regarding the very tight space on the control board has to be taken very seriously. There is very little space and removing a part would be almost impossible without damaging another one. Fortunately, I did not have to do that, yet.
Also, special care has to be taken when soldering because no leads or solder fillets may be higher than 1 mm on the bottom side of the board. Otherwise the control board may not fit onto the main board without scraching the MCU.
I got through it and it looks very good,I must admit. However, I don’t really understand why Elecraft didn’t use SMDs here. Maybe it has to do something with feasability during the manufacturing process.
I had quite some difficulties to fit the battery clips in the enclosure bottom cover. It turned out that I was trying to mount them from the wrong side… Don’t laugh… The picture in the assembly manual is a color image printed in black and white, so it was really difficult to see. I had to look in the PDF manual before I could see what I was doing wrong. In any case, when the manual says case face down it means that the inner face of the enclosure should be looking down on the table and the outer face should be looking up. Then you can slide the battery clips in from the top.
Also note, that when you assemble the ground screw, you need to use both flat washers not just one as one would believe when looking at the drawing. It’s pretty obvious though.