I thought I was smart. I thought buying a DIY 1176 clone kit from Hairball audio would save me a bit of cash. Well come to find out it isn't as easy as it looks and, despite my highschool-level understanding of electronics and acute attention to details in the build guide posted on Hairball's site, I find I've made a error in my build. I'm not going to exaggerate my knowledge here: I need help. Now, I knew a few things from the get-go. I knew that the power supply was working correctly and the +30 and -10 V test points were reading as they should and I also know that an input signal was going into the input transformer and came out at a lower voltage than was put in. This signal was also getting to the board however no signal was coming out of the unit. The VU meter was tested and both the light and needle were working as they should.
I had thought to go through the circut board and try to identify faulty components, and going through every component, I had found capacitors C21 and C4 to be shorted, and after waiting a few days for another mouser order to be delivered, I replaced the caps and wired everything back up. Surprise. There's no movement from the meter. However now when a signal tone is fed into the unit and the input knob is brought up, the signal can be physically heard coming from the output transformer. There is also a signal (don't know if it's the correct signal) coming from the output terminal.
My next attempt at fixing the problem focused on the meter board, thinking that maybe there was a bad connection between the board and the pins of the pushbutton mechanism, so I soldered the mechanism to the board. At this point I measured the power circuit test points and the -10V test point was reading correctly and the 30V test point was reading 23 V.
The next thing to happen was the unit failed to turn on and no power was even getting to the VU lamp. I chased this down to a blown fuse, tried another fuse and it blew as well. That was confirmed with continuity tests. I have checked the wiring again and again forwards and backwards, sideways and upside down. I really believe this has something to do with the board. Because I'm not an electronics aficionado I don't know any other way to diagnose issues other than the brute force way of testing every component. But because parts are failing in front of my eyes now, I'm afraid any further steps I take without complete knowledge of what is happening may damage the circuit further that it already is.
I know a little bit about electronics and how components work within a circuit, but I feel this issue that I face is a little too complex for my "current" understanding of this circuit. I've been researching for days on how to solve this problem. I've found nothing that I don't already know. So before I move forward, my questions here to anyone who can help is:
Is there any insight that anyone can give me on diagnosing my issue? Is there a more methodical way to find out what's going on within the board? Any other test points that can be used?
I've invested around 600 dollars on this thing and I'm not going down without a fight. I'm willing to start back at square one if I have to. Id be so grateful to anyone who can help. I'm so in over my head here.
I had thought to go through the circut board and try to identify faulty components, and going through every component, I had found capacitors C21 and C4 to be shorted, and after waiting a few days for another mouser order to be delivered, I replaced the caps and wired everything back up. Surprise. There's no movement from the meter. However now when a signal tone is fed into the unit and the input knob is brought up, the signal can be physically heard coming from the output transformer. There is also a signal (don't know if it's the correct signal) coming from the output terminal.
My next attempt at fixing the problem focused on the meter board, thinking that maybe there was a bad connection between the board and the pins of the pushbutton mechanism, so I soldered the mechanism to the board. At this point I measured the power circuit test points and the -10V test point was reading correctly and the 30V test point was reading 23 V.
The next thing to happen was the unit failed to turn on and no power was even getting to the VU lamp. I chased this down to a blown fuse, tried another fuse and it blew as well. That was confirmed with continuity tests. I have checked the wiring again and again forwards and backwards, sideways and upside down. I really believe this has something to do with the board. Because I'm not an electronics aficionado I don't know any other way to diagnose issues other than the brute force way of testing every component. But because parts are failing in front of my eyes now, I'm afraid any further steps I take without complete knowledge of what is happening may damage the circuit further that it already is.
I know a little bit about electronics and how components work within a circuit, but I feel this issue that I face is a little too complex for my "current" understanding of this circuit. I've been researching for days on how to solve this problem. I've found nothing that I don't already know. So before I move forward, my questions here to anyone who can help is:
Is there any insight that anyone can give me on diagnosing my issue? Is there a more methodical way to find out what's going on within the board? Any other test points that can be used?
I've invested around 600 dollars on this thing and I'm not going down without a fight. I'm willing to start back at square one if I have to. Id be so grateful to anyone who can help. I'm so in over my head here.
