Hi,
I assembled the mk103 kit, but cannot get it to work. It does not react to anything, except the leds flicker when I connect the battery. I haven’t modified anything, and actually assembled two kits, which both have the same behavior. Is it possible I have something backwards? I’ve checked all the soldering and everything seems fine - how could I troubleshoot the circuit?
Thanks,
Kasubo the newbie…
Hello,
Some things you can check.
Make sure that T4 is a BC557
You may also want to make sure that the LEDs are installed with correct polarity.
I hope this helps
The transistor is correct and the leds work on their own, so polarity should be ok. The trouble seems to be on the mic/amp side?
If you could post hi-res and sharp pics of your assembly (both component and solderside) we can take a look at your assembly.
Use a free web-based picture base to post pictures.
s954.photobucket.com/albums/ae24 … =FRONT.jpg
s954.photobucket.com/albums/ae24 … t=BACK.jpg
Not the neatest soldering job - I know 
Soldering is extremely poor. 99% sure this is at the cause of troubles.
Check for loose/forgotten/touching solderings. Make sure there are no solderbridges between two pads that should not touch. Make sure pads have not released due to overheating.
If necessary, have someone else inspect your circuit.
