I have the mk 124 msg kit. It seems that a few of the LEDs are not working. I am unsure about some of the soldering connections that overlap with the wires, eg. as the jump wires do. Is it possible to get the schematic circuit diagram to see for sure the connections?
Best wishes,
Alex M.
Hereby a link to the diagram and to the solderside, to look for shorts etc…
http://www.velleman.be/images/tmp/MK124.jpg
http://www.velleman.be/images/tmp/MK124solderlayer.jpg
-can you tell me the significance of the C2, C3,C4 capacitors?
I am trying to learn to understand circuits, I can understand digital logic, but not the role and importance of the capacitors.
-And is this the Ground connected to by the resistors R11&R12?
I am not sure if I am reading it correctly is it G||D or GND for ground
Third and last question 
-in digital circuits what do you need the ground for anyways and what can you use for it?
Thank you very very much,
Alex M.
(I look forward to buying more kits)
C2: part of RC oscillator for µcontroller clock
C4: smoothing of rectified AC
C3: decoupling for voltage regulator to avoid oscillation
R11 & R12 are connected to ground
Last question : ???
We are sorry, but we do not have the means to discuss circuit operation in detail.
Why do we need the C3 and C4 capacitors for oscillations when we have a DC power supply being fed into VDD from the power supply?
Thank you very much for your time,
Alex
I tried accessing the schematic from the links listed in the earlier post, but the files are no longer there. Can you post them again? I am using the mk124 in my electronics course, and the students could certainly benefit from the schematic during their troubleshooting activities. Thank you.
Hereby a link to the diagram.
Please allow 1h for server upload.
velleman.eu/images/tmp/MK124.jpg
