How to Diagnose and Repair Transistor Circuits - No Schematics. Dynacord Powermate 600
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- Опубліковано 31 тра 2022
- This Dynacord Powermate 600W Powered Mixer/Amplifier is stuck in protect mode. It has mainly discrete transitor cuircuits and have I have no schematics that match the version I have. But I still need to fix it. Here is a practical example of how to diagnose a difficult fault using nothing but methodical fault finding, basic electronics knowledge, some intuition and a multimeter!
Music in this video
Barbara Pennington - 24 Hours A Day (1976)
Learn Electronics Repair #249
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Thank you
Richard
outstanding, I love that you didn't try to edit it to make yourself look like a Tony Stark style genius.Its all about the journey. utmost respect.
I'm 73yr old and have been doing electronic repairs on medical equipment for 45 years. I helped in improving my knowledge of circuits by watching your techniques and drawing of schematics. Thank you for continuing to post on UA-cam.
The honesty of your channel is what I like the most. Real technician doing real repairs!
Richard, your videos are so awesome and authentic, why do you not have over a million subscribers. Keep up the great videos. Paul, USA
The ability to work without a schematic is what draws me to your videos. A Technician who can work using basic tools and logic is worth his weight in gold (as long as he's a f@t Bast**d). Thoroughly enjoyed the 2 hours..... I've always liked the analogy of water flow to describe DC through small circuits, and it occurred to me during this video that a bucket of water in a tree in East Yorkshire, +ve potential, has an equal and opposite bucket here in Australia. True Ground is not the dirt under your feet, but the centre of the earth where the water can finally rest= zero gravity, The Bucket in the gum tree is -ve potential with respect to Ground and the bucket up North. Loving the channel. Please keep it long and boring, as there are those of us that find this stuff fascinating,
You are a wonderful technician. You bring back a lot of memories for me. I am also a troubleshooter but +70 years old now and retired years ago. It is so refreshing to see real troubleshooting nowadays, rather then just shot-gunning component's or just changing modules.
Great example of real deal fault tracing, an unexpected burned path hidden under a bunch of components. They dont teach you this at school. I would not have found it. Thanks for the learning.
OMG ...
Hi from New Zealand! I found that thoroughly absorbing, especially with the successful conclusion. I am a 'fledgling electronics repair enthusiast, and just want to express my appreciation to you for your tutorials, which are invaluable to myself and, I'm sure, to others like me. Thank you for taking the time to 'educate' us electronics philistines, and please keep up the effort you put into these videos, it is truly appreciated.
just one of the best electronics channels i currently know
Very well done sir. After about 30 years on/off repair of consumer electronics I’m impressed. I loved how you were able to dissect the circuit down. Your lucky clue was the hot TO92 small signal transistor. But how you determined what actually was happening by your knowledgeable comparison side to side was brilliant. When it all lead to the open hidden trace and then your jumper wire correction I got excited! What a wonderful thing to see that protect light off, and then hear those relays click, it was the sound of success, “like beautiful trumpets to my ears!” The reward of hearing music in the end makes audio repair such a glorious thing. You definitely have one up on me in your knowledge of transistor configurations, and how they interact with each other. I loved how you were able to show us the bias voltages by comparing base to emitters even when dealing with a mix of positive & neg voltages, and how you were able to draw this all out and explain. I always use my flexible fiber light for inspecting pcb traces. However your break was in a most hidden place. Just goes to show how one really need to use all of ones senses, and be careful to be alert to all things/possibilities, as to not waste unnecessary time getting mislead in the wrong direction. You did this all without a schematic, I’m very impressed. I actually suspected shorted output transistors as the fault. Well done!! 😎👍
I have to admit I did dose off once bc I was very tired to start with, bit I just went and fixed a cup of coffee, came back rewound the tape anad continued all the way to end. Couldn't stand the mystery. Had to see how you fixed it, So glad I did, it was well worth the learning experience. Thanks Richard for another great repair video.
That was a quick couple of hours. Thank you for wanting to do this, I didn't see any wasted time and you got there without a circuit.
Thank you for your time and your helpful videos!
Watched from start to finished. That was a tough one. Great troubleshooting lesson.👍
Loved it! My lack of knowledge baffled me about half way through, but glad I can always come back to these videos to review and keep learning :)
One half of it one day and saw the rest the other, and I have to admit that I did fall asleep. I have to go back and review some of the video. Anyhow it was very educational thank you.
I fell asleep a couple of times ... only to wake back up, rewind to where I remembered, and go forward again. It's a great way to watch a 2'10" video in over 3hrs. Ha! But... it taught me a lot and I am grateful. I also learned tenacity and diligence. Maybe more important. Thx.
Didn't skip a single second. Excellent work and a satisfying conclusion.
Respect, sir. Respect... Beautiful video, without edit; very helpful. I learnt a lot. So, please continue, you gorgeous man....