What are the Bot Steps?
These little boards control the stepper motors and can blow from time to time with smoke and a loud crack noise, or no indication at all except suddenly you can not move in an axis or movement is erratic.
There are 4 on a single extruding Makerbot Replicator 1 or 2 (X Y Z + extruder A), and 5 on the Replicator 2X and Twin Replicator 1 (X Y Z + extruder A (right) and B (left))
What is looks like when they blow
There may be no physical evidence of a blown bot step on the board.
When blown they can fade a screen, cause lines through a screen, and effect motor movement.
Testing which one is faulty
BEFORE DOING THIS TAKE A PHOTO OF THE MOTHERBOARD. That way when you put them back in you will get the orientation correct. This is really important! If you suspect one has blown (and is taking down the screen or whole machine) it is easy to test
If the machine will not turn on or screen is dull or blank
1. Remove the bot steps one by one and turn the machine back on, then turn off and remove the next and turn machine on again. Continue until the screen turns back on. Do not replace them until the end as it could be more than one.
2. When you get to the point that the machine starts up properly start replacing the bot steps one at a time to see which ones are blown.
3. Then replace those ones with new ones (they are on our website - search Bot Steps)
If it is effecting movement, but not the screen etc, try swapping the Z Botstep with the one related to the bad movement (usually X as it works the hardest). If the problem resolves in the X direction, for example, you know that bot step needed replacing.
What if it is not the bot step causing the problem
Motor movement jerking, stepping and vibrating can also be caused by a faulty motor cable - see "motor movement section"
Screen problems may be the actually LCD assembly - type LCD into the search to see all the articles relating to that.
Where to get replacements
Bot steps : https://www.bilby3d.com.au/ProdSearch.asp?txtSearch=botstep
Motor cable: https://www.bilby3d.com.au/DispProd.asp?CatID=&SubCatID=126&ProdID=WRMR2CableXYZMotor
Motor cable rev 2: https://www.bilby3d.com.au/DispProd.asp?CatID=&SubCatID=126&ProdID=WRMR2CableXYZMotorRev2