Here are some measurements I took, I can always take more for you, I kept the top panel off until yours is fixed. I also took a picture of my board, not sure if it will help any.
V+ to gnd. = OL (infinite resistance)
V- to gnd = 6M ohm
On my MOSFETS, the drain pin is connected to the metal case of the MOSFET and I measure 0 Ohms.
The drain pin to ground = OL
The drain pin to heat sink = OL
Source pin to ground = 3.3M ohm
Gate pin to ground = 630 ohm
R15 is a jumper on my board and P5 is a fixed resistor of 475 ohms which provides an output gain of 20dB.
Check what you have and let me know, if the 22.1 ohm resistor smokes that fast there is a short to ground. Start by testing on both sides of R16 & R17 to ground. Make sure the source and drain pins are not shorted to ground first.
V+ to gnd. = OL (infinite resistance)
V- to gnd = 6M ohm
On my MOSFETS, the drain pin is connected to the metal case of the MOSFET and I measure 0 Ohms.
The drain pin to ground = OL
The drain pin to heat sink = OL
Source pin to ground = 3.3M ohm
Gate pin to ground = 630 ohm
R15 is a jumper on my board and P5 is a fixed resistor of 475 ohms which provides an output gain of 20dB.
Check what you have and let me know, if the 22.1 ohm resistor smokes that fast there is a short to ground. Start by testing on both sides of R16 & R17 to ground. Make sure the source and drain pins are not shorted to ground first.
Attachments
I think your tips and a second look has found this problem electrolytics incorrectly installed. I have an excuse however, This photo shows why. I don't understand how it happened, that will remain a mystery. I will correct this later today. Lucky I still had one unused board
Thanks again
Andy
Thanks again
Andy