Mk103 not working

Good afternoon… I’ve got two mk103 kits I’ve double checked everything and it seems ok from what I see. One unit doesn’t light at all and the other only lights as I first apply power by plugging in the battery.

Please let me know what I can check or troubleshoot.


Patrick Guice

Marlboro, NJ

Sorry, this forum does not allow picture uploads
If you can provide LINKS (e.g. by using a free online picture base) to HI-RES and SHARP pics of your assembly (both solder- and component side)
then we can take a look and provide some feedback.

Here’s the best I can do with the photo image as I don’t own a regular camera… I do see not perfect solder joints I did retouch up and still nothing. However I did meter out for continuity as well as voltage and continuity was OK, but I didn’t get voltage at some points including at the 4 LED’s. I’ve done three of these kits from Radio Shack and only one comes on only upon first powering up with battery. The other 2 are completely dead.

Thanking you in advance,

Patrick Guice … otostream/ … otostream/ … otostream/ … otostream/ … otostream/

Behind the mic t1 & t2 = BC547

Behind c4 t3 = BC547

In front of r9 = t4 = BC557

A couple of LEDs are mounted the wrong way round. Make sure flat side of led corresponds with flat side printed on PCB.
Soldering looks rather poor and might need rework.
If the problem persists, please contact our US support dept. at (817) 284 77 85