basic electronics question
rebuilding a Crate BFX100 bass amp. IRFP140 https://www.vishay.com/docs/91202/91202.pdf (at end of red trace) N channel Output MOSFET was blown (shorted) so I replaced it. Checking the other passives before I powered it up I noticed that a .1ohm 3W cermet resistor R53 was in series and the ohm value was way off, like shorted 0 ohm. This is on the -40V DC leg going straight to the source pin of the MOSFET. What should this -40V voltage be through the .1ohm 3W resistor at the S pin of MOSFET Q6? I think this resistor going to short caused the MOSFET to get full -40V causing it to blow? Zener diodes D16-17 changing anything? Voltage drop through a resistor? 15V AC is test point value of Drain pin per schematic.
@KitCarlson
rebuilding a Crate BFX100 bass amp. IRFP140 https://www.vishay.com/docs/91202/91202.pdf (at end of red trace) N channel Output MOSFET was blown (shorted) so I replaced it. Checking the other passives before I powered it up I noticed that a .1ohm 3W cermet resistor R53 was in series and the ohm value was way off, like shorted 0 ohm. This is on the -40V DC leg going straight to the source pin of the MOSFET. What should this -40V voltage be through the .1ohm 3W resistor at the S pin of MOSFET Q6? I think this resistor going to short caused the MOSFET to get full -40V causing it to blow? Zener diodes D16-17 changing anything? Voltage drop through a resistor? 15V AC is test point value of Drain pin per schematic.
@KitCarlson
