Badcaps Forums - View Single Post - troubleshooting definitive technology prosub 60

**R_J** · 09-26-2020, 07:48 PM

If Q1 & Q7 were shorted and R19 open, it is very likely the gate drive circuit is also damaged, Z1, Z4, R1, R18, Q3, Q4, Q5 etc. Z1&z4 are zener diodes and may check like a diode but zener at the wrong voltage.
If Q1 or Q7 shorts drain to gate, it applies 170vdc to the gate components, so it may have damaged U3d as well

09-26-2020, 07:48 PM	#2
R_J Badcaps Veteran Join Date: Jun 2012 City & State: ☻ My Country: Canada I'm a: Professional Tech Posts: 6,765	Re: troubleshooting definitive technology prosub 60 If Q1 & Q7 were shorted and R19 open, it is very likely the gate drive circuit is also damaged, Z1, Z4, R1, R18, Q3, Q4, Q5 etc. Z1&z4 are zener diodes and may check like a diode but zener at the wrong voltage. If Q1 or Q7 shorts drain to gate, it applies 170vdc to the gate components, so it may have damaged U3d as well Last edited by R_J; 09-26-2020 at 07:56 PM..