Well I’ve been looking over the Rock-Mite kit for the past few days wracking my brains trying to figure out what’s wrong with it.
After two days of searching/checking each part I finally noticed that R6 had blown, there were burn marks all over the base, difficult to see without a magnifying glass but it would correspond to the smoke I saw when first firing the rig up. So I have removed it and am currently purchasing a new 10 ohm resistor.
After joining the Yahoo Rock-Mite discussion group and informing them of my problem, they were extremely helpful and various suggestions and tests were carried out as advised by some of the experts. Nothing was found and after doing numerous searches for shorts and bad connections I have to be honest here I was on the point of giving up.
Then this morning before going to work I was reading up on the manual to see if I had missed anything and there in front of me was a photo of the PCB with the two IC’s U2 and U3 seated in the board, I looked at the numbers on the chips in the photo and then looked at the numbers on my circuit board……… they were the wrong way round!
How could I have missed that? Well I did and what an embarrassment, but it just goes to show that you need to check everything and never assume the obvious because guaranteed it will be the culprit.
Tonight after reinstalling a new resistor I will attempt another smoke test and I’m guessing even being a novice builder that should sort the problem. I will obviously update this post once I have the result.
I am very embarrassed with such a stupid mistake but at the same time enormously relieved that at least I have possibly found the issue and I am not going nuts! More updates to follow soon.