MK190 2X5W stereo amplifier - Speaker output malfunction


#1

Hello
I received the MK190 kit as a gift. After finishing the assembly process i tested it and it had a problem with the right channel output. Basically if both sekaers were connected, only the left one produced any sound. If i disconnected the left one, some sound would come out of the right speaker, but at really low volume. At first i thought the problem was the right channel capacitor, i even tried placing the positive terminal of the right speaker before the capacitor on the circuit board and i got some sound, but by doing so i would only get sound from both speakers for a couple of seconds, and then it would simply fade out to complete silence. At this point i tried to replace the capacitor on the right channel with a new one, but after replacing it, nothing changed. Unfortunately during the removal of the old capacitor, i ruined the conductor on the circuit board, but even by byassing said conductor completely and connecting one pin of the capacitor directly to the correct pin on the amp the result wouldn’t change. I had the connections checked by someone more experienced than me and they seem to be fine
Based on my VERY limited knowledge and experience, i think that the circuit has trouble keeping the capacitors charged up, even if i used a 13.8 volt 5 Amps power supply. As a source i used the record output of my amplifier and the speakers have an impedance of 8 ohms, so everything should be within specs. I even ran the amp with different power supplies with variyng voltages (i tried 6 and 7.5), but the results never changed.
Any suggestions? Is it possible that i irreparably damaged the device? Is it possible that i encountered a faulty unit?
Thanks


#2

Hi could you post pictures of your board please? Top and bottom.

Thnx!
VEL337


#3

20180117_111120

20180117_110844

20180117_110832https://ibb.co/nksiRm


#4

Im having a similar problem with the same amplifier. Im getting sound on the left speaker, and very very low (sometimes) on the right. If I connect the left speakers wire to one of the ports on the left, and on one on of the ports of the right I get sound, but if I connect wires only to the left nothing, or in best case extremely low. I have the exakt same issue on my two MK190. Any advice?