When I get home in a couple of hours, I'll take some measurements on my BZLS and will send them to you. Pics look fine and my cheap tablet zooms in for details.
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