The “DOA” failure rate of the actual LEDs is very low– if we were to install 1000 in a panel, we would expect zero failures. However, they can be damaged by overheating or by physical stress.
Is it possible that your soldering iron tip is not *shiny*? If your tip is not tinned well, that can lead to poor wetting, and may mean that you need to heat the joints for significantly longer than the 1 second (or so) that we recommend. We recommend *never* to reheat/reflow a solder joint unless it is known to need repair. We’ve had a lot of experience helping people get their kits up and running, and from that experience we can say that reheating components and removing parts (not certain to be damaged) are the two most common ways that components and the circuit board itself get damaged.
You can download the Bulbdial electrical schematic (PDF) from our documentation page:
The relevant part is the LED matrix, visible on the first page of the schematic. From this you might be able to see (for example) that if D16 were damaged or missing, D12, D13, D14, and D15 would be expected to light dimly. However, if there are short circuits or more than one or two damaged components, it can get pretty difficult to identify where the issue is.
In cases like this what we normally do is suggest that you do is to contact customer service directly ( http://shop.evilmadscientist.com/contact ). We can send you some replacement blue LEDs, or sell you a replacement blue board with its components at a significant discount.
