@mrehorstdmd said in recent issue heating bed..funny smell:
@gnatman The bed plate acts as a heatsink for the heater. If the heater detaches from the plate or develops an air bubble between the heater and plate, the heater won't be able to transfer heat to the plate and the heater will get extra hot in that area. I'd inspect the bed and heater carefully to see if there are any areas that have let go.
I had this happen after about 2 years operation:
The acrylic adhesive on the heater dried up and let go of the plate. The silicone/glass heater scorched in the area where it detached from the bed plate. The outside surface of the heater looked fine- only the inside surface was burned, but the air bubble was obvious. I never noticed a smell, but the printer is usually closed when it's operating.
When I replaced that heater I ordered the new one without adhesive and used high temperature silicone to attach it to the plate. It's been about 2 years now and there are no signs of the silicone letting go.
Here is the underside of the bed, looks fine to me. not even a short on the thermistor. I checked the power and neg on the bottom of the bed and re-soldered the neg wire just to be safe.