Good day guys, this power supply uses K1420 with 47ohms gate resistors, I can’t get those in my area to replace the bad ones. What other mosfet is suitable with this arrangement that I could just drop in, need for a more superior mosfet is also endorsed.
Do you need fully encapsulated?
I'd remove that brown fixative. It's likely conductive and corrosive.
I'd remove that brown fixative. It's likely conductive and corrosive.
It was clamped to the heat sink, you told me metal backs are way more reliable in heat dissipation than encapsulated packages, I’m cleaning the board now as we speak.
The thermal conductivity is better with bare metal but you have to take into account the insulator in the amp. After looking again, it doesn't appear that they were screwed down (so no need for fully encapsulated). I think I'd use the IRF3205 with an insulator.
Are you referring to the resistors connected directly across the output of the driver IC?
If so, how/why would you change their value?
If so, how/why would you change their value?
It’s exactly how you said it Sir Babin, I had a clear memory of that arrangement as I was on that specific area extensively while repairing the amp, infact my FETs on the thermal sensor side was becoming heated gradually too fast, when I checked, the zener diodes (39v) was leaking on both side of amp, I’ve replaced them then all FETs was cooled.
It took me…
6 3205 replaced K1420 all failed
2 A733 replaced A1266 one failed
6 47ohms half watt resistor five failed
2 1N4754A (39v zen) both failed
5 major capacitor (input smoothing & rail out)
….and of course ever-sharing knowledge from Sir Babin and the rest of the team.
6 3205 replaced K1420 all failed
2 A733 replaced A1266 one failed
6 47ohms half watt resistor five failed
2 1N4754A (39v zen) both failed
5 major capacitor (input smoothing & rail out)
….and of course ever-sharing knowledge from Sir Babin and the rest of the team.