Hey guys, can anyone, just based on their experience, tell me where should I start in trying to identify the following issue. Sub worked normally prior to this and nothing specific happened in between (like loss of power or something). It worked in the evening, turned off on a switch, then when turned on the next morning it started doing this.
I believe that the video is the best way to describe what's happening: https://www.dropbox.com/scl/fi/7vkc...nger.MOV?rlkey=yi8w2lbpc242or2b4rb7h1etn&dl=0
I obviously don't have a schematics and I would simply like to try to fix, won't die without it. I have some experience with electronics so I believe I will be able to test/remove/replace any component that can be tested with a UNI-T UT70B.
What I figured out so far:
- 1 component was missing, 47nF Capacitor next to the 4 'big' diodes, diode bridge? I've marked it in one of the photos. Capacitor was broken from it's pins, probably fell off from the sub at some point. I have replaced it (new one is on the image), but nothing has changed, same buzz before and after.
I would like to know where would a repair expert start? Could have that 1 Capacitor, while missing, caused damage to some other component? Should I replace all 4 'large' diodes or test them while removed from the board? Replace big capacitors? Should I somehow test the transformer?
Without any extensive experience, I would start by replacing all 4 big diodes and their capacitors, and while ordering components, I would also order these 4 largest capacitors and replace them as well, but I would get stuck if that doesn't do the job.
Any idea is highly appreciated! Thanks!
I believe that the video is the best way to describe what's happening: https://www.dropbox.com/scl/fi/7vkc...nger.MOV?rlkey=yi8w2lbpc242or2b4rb7h1etn&dl=0
I obviously don't have a schematics and I would simply like to try to fix, won't die without it. I have some experience with electronics so I believe I will be able to test/remove/replace any component that can be tested with a UNI-T UT70B.
What I figured out so far:
- 1 component was missing, 47nF Capacitor next to the 4 'big' diodes, diode bridge? I've marked it in one of the photos. Capacitor was broken from it's pins, probably fell off from the sub at some point. I have replaced it (new one is on the image), but nothing has changed, same buzz before and after.
- All other components LOOK normal, no blown capacitors or burned resistors, visual inspection is good.
- I believe buzzing is not related to the input module because it behaves the same with or without it (I've disconnected it in the video)
- I can see a red LED next to transistors light up, it's on the board itself, could that mean something? Maybe that diode is a 'debug' info on some amplifiers?
I would like to know where would a repair expert start? Could have that 1 Capacitor, while missing, caused damage to some other component? Should I replace all 4 'large' diodes or test them while removed from the board? Replace big capacitors? Should I somehow test the transformer?
Without any extensive experience, I would start by replacing all 4 big diodes and their capacitors, and while ordering components, I would also order these 4 largest capacitors and replace them as well, but I would get stuck if that doesn't do the job.
Any idea is highly appreciated! Thanks!
Just hypothetical conclusion.