Ok final update on this with conclussions. Summarizing: Client states that one of the functionalities of the board (pellet ash cleaning motor) is not starting, neither during normal operation, nor during tests screen,
There is one relay in a row of several, that clearly drives the 230V ac voltage to the cleaning motor. Before any other test, I try to apply 24v dc to all relays directly and they all click on-off but this-supposedly-faulty -one goes like slow and weak. I measure all driver transistors and all give the same readings but the ones driving this relay. It seems that 2 transistors drive each relay in aparallel like and OR gate.,
I replace these 2 transistors and turn the board back to the client.
He tried it yesterday on the boiler and called me to state....: IT ALL WORKS PERFECTLY NOW!!
So somehow I may have damaged these transistors but they were already damaged because just by replacing them the board came back to life...
Despite being my fault or not my conclussion is that I still don't master the abilities to repair an electronics board as some of my testing techniques are dangerous...That's why even when I believe I can go ahead with some repair, I always come to this forum to get some assistance. In this case I tested the relays before...
Thanks everyone!!
There is one relay in a row of several, that clearly drives the 230V ac voltage to the cleaning motor. Before any other test, I try to apply 24v dc to all relays directly and they all click on-off but this-supposedly-faulty -one goes like slow and weak. I measure all driver transistors and all give the same readings but the ones driving this relay. It seems that 2 transistors drive each relay in aparallel like and OR gate.,
I replace these 2 transistors and turn the board back to the client.
He tried it yesterday on the boiler and called me to state....: IT ALL WORKS PERFECTLY NOW!!
So somehow I may have damaged these transistors but they were already damaged because just by replacing them the board came back to life...
Despite being my fault or not my conclussion is that I still don't master the abilities to repair an electronics board as some of my testing techniques are dangerous...That's why even when I believe I can go ahead with some repair, I always come to this forum to get some assistance. In this case I tested the relays before...
Thanks everyone!!
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