<![CDATA[SoliForum - 3D Printing Community — Need new mosfets--bed won't heat]]> https://www.soliforum.com/topic/17872/need-new-mosfetsbed-wont-heat/ Tue, 22 Jan 2019 06:36:21 +0000 PunBB <![CDATA[Re: Need new mosfets--bed won't heat]]> https://www.soliforum.com/post/148591/#p148591 One MOSFET controls the bed heater power, another controls the hot end power; they're both an IRLB8743.

Here's one on Adafruit for $1.75:
https://www.adafruit.com/product/355?gc … 3_EALw_wcB

...and from Mouser for $1.40:
https://www.mouser.com/ProductDetail/In … Z2TQ%3D%3D

It's a pretty straightforward solder job.

Every Printrboard I've ever seen has a small piece of kapton tape over the heatsink of the heatbed's MOSFET, and none on the hot end's.  I do not know why.  The circuits for the hot end and heatbed MOSFETS are identical.  The heatsinks are electrically connected to the MOSFET's drain, and so will have 12vdc on them when their respective heater circuit is off.

As long as the heatsinks aren't touching each other, or anything else for that matter, you should be fine.

-Kevin

]]> Tue, 22 Jan 2019 06:36:21 +0000 https://www.soliforum.com/post/148591/#p148591 <![CDATA[Re: Need new mosfets--bed won't heat]]> https://www.soliforum.com/post/148586/#p148586 Morganism wrote:

Hello,

The heated bed on Solidoodle 4 stopped working. Sliced and programmed to turn on, but nothing happens. It prints fine, if I don't turnthe bed on. I know there could be other issues, but it was recommended to me to start by replacing the mosfets for the bed. I am comfortable doing this, but I don't know where to get them or what the specifications are?

Any advice/links would be helpful.

Thank you in advance...


If you insist on replacing them the part number is on the part. Just go to Mouser or Digikey and enter that number.

]]> Mon, 21 Jan 2019 22:48:41 +0000 https://www.soliforum.com/post/148586/#p148586 <![CDATA[Re: Need new mosfets--bed won't heat]]> https://www.soliforum.com/post/148585/#p148585 Probably cheaper and easier to replace the board.  So many choices like Ramps or Rumba.

]]> Mon, 21 Jan 2019 21:36:21 +0000 https://www.soliforum.com/post/148585/#p148585 <![CDATA[Need new mosfets--bed won't heat]]> https://www.soliforum.com/post/148584/#p148584 Hello,

The heated bed on Solidoodle 4 stopped working. Sliced and programmed to turn on, but nothing happens. It prints fine, if I don't turnthe bed on. I know there could be other issues, but it was recommended to me to start by replacing the mosfets for the bed. I am comfortable doing this, but I don't know where to get them or what the specifications are?

Any advice/links would be helpful.

Thank you in advance...

]]> Mon, 21 Jan 2019 21:09:19 +0000 https://www.soliforum.com/post/148584/#p148584