# Lulzbot Mini Bed Leveling Issues **URL:** \ **Category:** Software\ **Created:** [May 21, 2017, 8:05pm UTC](https://forum.lulzbot.com/t/lulzbot-mini-bed-leveling-issues/4905 "2017-05-21T20:05:01Z")\ **Posts on this page:** 1\ **Showing post:** 2
**Author:** ![ScottW](https://avatars.discourse-cdn.com/v4/letter/s/53a042/32.png) [@ScottW](https://forum.lulzbot.com/u/ScottW)\ **Post date:** [May 22, 2017, 12:01am UTC](https://forum.lulzbot.com/t/lulzbot-mini-bed-leveling-issues/4905/2 "2017-05-22T00:01:07Z")
The behavior you describe is typical of a blown mini-Rambo board. That usually happens when there is a short between the heater wires and the nozzle, which sends heater current to the board ports used to detect the nozzle touching the washers. The fix for that is to replace the mini-Rambo board. This frequently happens when someone uses a wire brush to clean the nozzle. The brush wires penetrate the insulation of the heater wires, short the current to the nozzle, and destroys the portion of the board used to detect the nozzle/washer touch. The board then reports to the firmware that the circuit is closed (i.e., that the nozzle is already touching the washer) so the probing sequence never proceeds down, and firmware sets the washer position to the starting position (well above the bed). There are several threads here warning not to use a “wire brush”, so you might search those to compare/confirm symptoms. If it is the board, Lulzbot or [itworks3d.com](http://itworks3d.com) should be able to sell you a replacement board. --- _[View the full topic](https://forum.lulzbot.com/t/lulzbot-mini-bed-leveling-issues/4905)._