…with my own designed power supply. Although two of them are already working, in the third machine I get a shortcut between analog and digital ground which results in muting the sound. I came up with the idea of a better separation with optocouplers and while a prototype is working the final pcb is not.
Really no idea how to continue, since I am not the hardcore expert in electronics. I would have loved to study electronics and I already enrolled but, back those days, I had a severe traffic accident and instead learned a couple of years to walk again. So if anyone is eager to help… 😊
Anyway, during testing one of my laboratory power supply broke and I had to repair it first. Crazy enough, the circuit of this Paektech 6225a contains a Zener diode with an ultra low resistor. It is only a question of time when this diode will brake due to high current, therefore I also replaced the resistor to 50R. I am unable to find the original resistor and cannot remember but it had about 3R?!. The problem with the power supply was that, although it is possible to set the voltage and current, when you enable the output, the voltage returns to zero. Without a circuit diagram I identified transistor Q25 as not working. According to my measuring I was able to identify it as an NPN transistor and replaced it with a BC848 and it is back working.
I also ordered tons of capacitors before Trump will introduces his taxes on EU import/export. He’s a fanny. For the future I have to find another supplier since I expect the prices to increase a lot. Fun fact, it is a surprise when you had a typo in the order and ordered 114 pieces of 47uF/50V capacitors instead of 14. Guess I have never ever to order one again.
…and finally, I invested into a smoke exhaust ventilation. Think my health should be worth the investment. I always get dizzy during soldering. Reckon this costed my a couple of years of my lifetime.
Somehow a total mayhem. In addition, my new job occupies a lot of my time and the progress is very slow…
