i have a problem with my hifonics brutus bxi 1100d.after output fet failure,the gate signal of one high side bank is not clean and the fets get hot(the two with the heatsink).the other high side and the other both low side gates are ok.i replaced the fets,the gate resistor,the hip4080,the lm393 left of the hip4080,the lm833 and the 6,2v zener diode"ZD1".this diode gets relatively hot,about 100 degrees.on another amp its only 50 degrees
the amp works,but sounds distorted.see the photos.pic 175705 good gate
pic 175712 bad gate
what could be the problem?
the amp works,but sounds distorted.see the photos.pic 175705 good gate
pic 175712 bad gate
what could be the problem?
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Sometimes a mosfet blowing will take the driver with it too.
I have worked on a lot of irs2029 based amps and changed the 2092 as a matter of course when a mosfet went.
Or it could be the high side mosfet partly blown ?
I have worked on a lot of irs2029 based amps and changed the 2092 as a matter of course when a mosfet went.
Or it could be the high side mosfet partly blown ?
I'm sure you must have replaced the above parts correctly, but I still suggest you check for shoot-through, as components pertaining to the inverter are now different from before. I hope you changed the bootstrap diode and capacitor as well.
Connect a high value series resistor (say 1k) to the inverter section while operating at no-load (speaker) and see if the heat persists. Also check the voltage across this (test) resistor. In case it contains any spikes, adjust the dead-time until they are no longer present (no shoot-through).
Opinions vary, but whenever I replace MOSFETs, I replace both devices of a leg together and also make sure to use devices from the same batch to avoid discrepancies related to switching times.