Heated Bed not working correctly after update

[ZeroMavr1k]

After updating printrbot simple metal. My heated bed when at temperature consistently turns on and off rapidly I can hear the relay clicking on and off on and very quickly. I did not have this issue prior to updating heated bed worked fine.

Any thoughts?

[Zakattacks]

The firmware is designed to use the integrated MOSFET in the Printrboard (See this article for more:Reprap forums:Using relays for hotend and bed gives unexpected results)-- To use a relay, you have to change the config and re-compile as seen here: MarlinFirmware Issue 267
Best solution is to upgrade to an external MOSFET if you're not able to use the built in one. A standard DC SSR (Solid State Relay) such as the ubiquitous SSR-25-DD should work fine.

[ZeroMavr1k]

Ah I see. Thanks for the response. I am currently using a different power supply for my heated bed.
So I guess i have some figuring out to do.

[Zakattacks]

The SSR would be a drop-in replacement for the relay in your relay. You might need a heatsink for it.