howie
Junior Member
Posts: 87 
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Post by howie on May 25, 2019 8:18:24 GMT -5
So I have this Proceed 5 Ch amp that is not popping fuses but is banging out on protection. When you turn it on via the hard power button, it powers up in standby mode fine. But as soon as you push the soft power button, it goes quickly into protection mode. I quickly narrowed the problem down to the left rear amp module by unplugging it and removing it. It's modular so to be sure I wasn't chasing my tail, I moved a working module into it's slot. It's all through hole stuff and pretty easy to look at. Each module has 9 electrolytic caps in 3 different sizes. I can usually spot a bad cap right off the bat. Every one of them looked perfect Zero swelling or leakage. Couldn't find my ESR meter quickly so I pulled all 9 and tested them with a regular capacitor tester. All reasonably OK (capacitance wise) Now where's that ESR meter??? After turning my shop upside down to find the meter, I started testing The 2 10uf 50v caps read 9uf but one was 26.3 ohms and the other 16.2 ohms YIKES. A 470uf 16v was 456uf 12 ohms all the rest were 1-4 ohms. Still high so I ordered enough low ESR caps to do the whole thing, starting with the bad on to see if it will fire up.
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Post by mastertech on May 26, 2019 19:24:27 GMT -5
Hey stranger. How are things? Keep us updated on your findings and results.
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howie
Junior Member
Posts: 87
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Post by howie on May 27, 2019 8:37:22 GMT -5
Hey stranger. How are things? Keep us updated on your findings and results. SOS. I only take on interesting projects these days. This Proceed amp was given to me. The only enjoyment I'll get out of it is fixing it. I have piss poor hearing, so high end audio is out for me. Huge waste of money. I no longer have any interest in analog video. It was fun while it lasted but now with huge 4K digital video flat screens, there's just no reason for me to putz around with CRT projectors. Getting close to retirement. Need a new hobby. Tossing around the idea of rebuilding salvage high end autos. |
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Post by mastertech on May 27, 2019 20:04:51 GMT -5
Interesting. What are you calling high end autos?
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howie
Junior Member
Posts: 87
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Post by howie on May 28, 2019 6:03:02 GMT -5
Interesting. What are you calling high end autos? I enjoy working on late model Corvettes. |
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Post by mastertech on May 29, 2019 20:27:22 GMT -5
Sounds like fun. Enjoy.
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howie
Junior Member
Posts: 87
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Post by howie on May 30, 2019 17:00:44 GMT -5
How'd I miss this one I removed all the caps from this amp and tested them out of circuit. Was cleaning the floor under my desk and found a 68uf 63 volt capacitor. I know thee's 9 caps per block and there was only 8 in the dish. So lets drag out the Peak ESR+ ESR70 meter again and test this one It's a 68uf cap that read 56.46 AND 40ohms resistance Eeeeyowsa Now that might be enough to set protection mode.
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howie
Junior Member
Posts: 87
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Post by howie on Jun 1, 2019 5:03:49 GMT -5
I thought it was a bit odd that the ESR meter displayed exactly 40.0 ohms when I tested it. Come to find out, that's the limit of the meter so that cap has somewhere more then 40 ohms. That's the first cap that's pegged my meter. Not sure what parameters set a Proceed amp to go into protection mode but this is a good place to start
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howie
Junior Member
Posts: 87
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Post by howie on Jun 5, 2019 18:21:17 GMT -5
Well sheeeeet. Replacing the bad caps didn't resolve it. Going to have to dig deeper. And I don't think service manuals are available for these.
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Post by mastertech on Jun 6, 2019 11:22:59 GMT -5
Got a picture of that amp module?
Also see if there is another brand name on the circuit board. If we can see who made it might be able to match up a schematic.
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howie
Junior Member
Posts: 87
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Post by howie on Jun 9, 2019 10:54:02 GMT -5
perhaps this will help. Will have to pull it out again to look for additional information  |
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howie
Junior Member
Posts: 87
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Post by howie on Jun 9, 2019 12:54:08 GMT -5
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howie
Junior Member
Posts: 87
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Post by howie on Jun 9, 2019 15:03:11 GMT -5
Can all those transistors be tested in circuit or do they have to be removed???
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Post by mastertech on Jun 9, 2019 17:20:42 GMT -5
If any of them test shorted in circuit then it would have to be removed and retested out of circuit.
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howie
Junior Member
Posts: 87
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Post by howie on Jun 19, 2019 18:13:33 GMT -5
I need a Madrigal service manual for this. Anyone have friends in low places???
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