Originally Posted by force of 1/2
Is it at all possible that just only R25 was fried?
I used a rather small resistor in that position. It may be 1/8 watt.
Is there an easy way with a DMM to test Q3/4 and Q9/10?
I ask only because with the thick PCB, it may be best to try and replace as few components as possible.
It could be that only the resistor died. But in my experiments during rev2 development with manually inducing hard overloads I noticed that whenever either of these resistors dies it takes Q3/Q4 with it, but rarely Q9/Q10. Interestingly, both Q3 and Q4 would pass the base-emitter and base-collector diode test, but as soon as I power it up after replacing only the resistor, it would get burned again, but not after replacing Q3/Q4. So I would suggest that if you replace this resistor then also replace Q3/Q4.
Edit: do not run them at least until installing the rev2 mod as well.
Last edited by shaan; Yesterday at 08:56 PM.