amateur_24
Member
Hi
So I had a short circuit accident whilst servicing my 3d printer. This killed the MOSFET controlling the heated bed. Hence I needed to reconfigure the firmware to send the on signal to a different pin then wire it to an external SSR.
So the SSR is opto isolated. It uses 4n35 in a dip package. There was two inputs on the controller side. So I hooked it up to an input confusingly labelled + - bed. I would expected to be labelled signal. But nvm.
I have checked the input labelled bed isn't connected to the much better terminals on the other side as this would send 13v to the CPU. I know it doesn't appreciate it.
However when I turned everything on nothing happened. The led on the bed didn't light up.
I then checked to see if the input had volts on it. Because maybe I configured the firmware wrong or plugged it into the wrong pin.
But as soon as I pushed my the probes across the the input terminals, the bed led lit up but when I removed my probes it went away. I continued to repeat this because I thought I was going crazy. It the was round about then, the web interface lost connection to the controller.
Today whilst replacing the controller, I discovered the controller had cracked solder joints on both the vin positive and negative. I suspect that's why it turned on when pushed down with my probes. So could the on and off action fried my CPU?
So I had a short circuit accident whilst servicing my 3d printer. This killed the MOSFET controlling the heated bed. Hence I needed to reconfigure the firmware to send the on signal to a different pin then wire it to an external SSR.
So the SSR is opto isolated. It uses 4n35 in a dip package. There was two inputs on the controller side. So I hooked it up to an input confusingly labelled + - bed. I would expected to be labelled signal. But nvm.
I have checked the input labelled bed isn't connected to the much better terminals on the other side as this would send 13v to the CPU. I know it doesn't appreciate it.
However when I turned everything on nothing happened. The led on the bed didn't light up.
I then checked to see if the input had volts on it. Because maybe I configured the firmware wrong or plugged it into the wrong pin.
But as soon as I pushed my the probes across the the input terminals, the bed led lit up but when I removed my probes it went away. I continued to repeat this because I thought I was going crazy. It the was round about then, the web interface lost connection to the controller.
Today whilst replacing the controller, I discovered the controller had cracked solder joints on both the vin positive and negative. I suspect that's why it turned on when pushed down with my probes. So could the on and off action fried my CPU?
