I purchased a mk104 and assembled it. After assembling it I turned all the pots to the lowest value and plugged in a 9v battery. Instead of hearing criket noises the electronic produced an awful screeching noise. I have uploaded a video to show:https://vid.me/14Vk How can I go about debugging it?
Hard to say what’s going on.
You should post some clear pictures of the top and bottom of the kit.
Remove the battery holder and the buzzer so all of the solder joints and components show.
Here is a link to some photos:
http://imgur.com/a/J3pUb
The soldering needs a lot of help.
You need to melt the solder until it flows and covers the pad.
Do not stay on the joint to long as this will damage it.
You should download the manual from this link for help.
http://www.vellemanusa.com/downloads/0/user/usermanual_edu03.pdf
Yes I too noticed that my solder needs help.
I’m not sure if this happened because of the parts I used or because of my bad soldering technique. I used a Aoyue 469 with the stock tip and at a power of 5 out of 9 with some pretty low quality rosin core solder I bought from Walmart.
Should I try getting nicer equipment or is it just bad technique? If it’s bad technique how can I improve it?
I have redone the solder connections on the board (I bought better solder and put the iron at a higher temperature). You can see what it looks like now: imgur.com/a/7VWUD. One thing I still don’t know how to do is fix the solder bridges between the components (I have circled the area I am talking about with red circles). How can I go about fixing them?
Also, now when I plug in the board it makes a noise that gets high pitch, then goes down to a low pitch hum, and then just crackles. I have attached a video to show: vid.me/Pzcc . Interestingly enough if I unplug it and replug it back in immediately I only get the crackle noises, but if I wait 10 or so minutes and plug it back in I will get the high and low pitch hum again. My guess is this has something to do with a capacitor.
How can I go about fixing this?