i have a very nice vintage DBX BX3 amp on which at least one channel fused.
power transistors literally burned down.
it is a very nice piece of hardware (4 channels with BTL capability 4x125W or 2x300W)
I would like to fix it myself. Having an electronic engineering degree, i think I should be able to undertake that venture but I never practiced (i've been in software for the last 40 years...)
So I need some guidance on the methodology to diagnose and track what went wrong.
I do have a scope, signal generator and I guess all required tools, as well as the schematics of the amp.
what I need is some help on locating the key parameters to measure and how to incrementally explore the different stages of the amp to find the faulty sections.
I guess I need to isolate the different sections of the amp but then, what ?
any help and advice will be highly appretiated.
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hi zsugori,
thx a lot.
i took yesterday a closer look to the amp board and i saw a large number of resistors and transistors burned so I will need to remove and replace most of components ...
that will keep me busy a few days ;)
are any measurement refernece points on the board we can use to check it is working properly ?
regards
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1x2x125w nem elég?
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Hello,
First try it with regulated (Constant current) power supply and dummy load.
Measure voltages at the pins of transistors.
tj
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of course !
i should have thought about it right away !
newbies in the business ;)
thx a lot
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Make sure you buy original semiconductors. There are many fakes.
Good luck!
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few more questions
- i spotted and removed several burned components
- is there a simpler way to detect fused/damaged components on the board without removing and testing them individually ? without powering the board ?
- if I power the board, without the damaged components do I have a risk of damaging more (my initial thought would be that it does not make sense and measures will be meaningless) ?
- what would you use to remove incrusted dust and clean the board and components ?
regards
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