I just added a heated bed along with a new power supply (EVGA 430W) and using the 16_32_090615 firmware I changed EFF to EFB along with enabled my heat bed temp sensor (using type 11 as suggested by the place I bought it from) and uploaded that without issues to the Arduino board with only USB connected at this point.
Following many of the guides online I isolated the +12V pins and GND pins (they were originally attached to the CPU plugs, 8 wires total, I’m only using 4 of them) along with wiring the green PS_ON to GND to make the power supply turn on when the exterior switch on the power supply is turned on. All that seems to work just fine, the power supply comes on, the +12V lines all register 12.18V with a multimeter.
I then connect those 4 wires up to the green RAMPS plug as +12V,GND,+12V,GND (first +12V is the one closest to D8).
Plug all that in and power everything up, RAMPS board lights up and connects to computer just fine, stepper motors work fine.
Enabled heated bed and it’s light comes on and starts heating up the bed, temp sensor registers the temp change, Extruder heats up also when enabled and temp registers properly for the extruder also.
D8 == Heated Bed
D9 = Empty
D10 = Extruder 1 (I only have one Extruder)
Only problem is one or more of Mosfets heat up almost immediately and at one point the extruder overheated, I think I caught it in time though and powered everything off again. After letting things cool down I powered it all back up again and the Mosfets instantly heat up each time.
One of the wiring guides for RAMPS1.4 and PC power supply suggests a 47 Ohm resistor on the green PS_ON line to achieve soft power on which is the only thing I didn’t do as I didn’t see that suggestion until later when troubleshooting. Most of the other guides I looked at online just mentioned connecting the green PS_ON to a single GND line and calling it done.
With all that info any suggestions on what I did wrong or what I should do now?
I’m guessing at least one of the Mosfets need to be replaced now but what did I do to destroy it?