I was doing a print about two weeks ago that engulfed my print head in a nasty plastic glob… when I came in to check on it, the print was knocked off the bed and there was a glob on the nozzle. Given it was still hot, I tried to pull the soft plastic off the nozzle… unfortunately, apparently the shroud had melted and came off as well (1st pic). Worse, as I was trying to clean it out, a shower of sparks erupted from the nozzle (presumably something with some power, perhaps the heating element wire, had shorted). This reset the printer, and I turned it off. I figured the print head was toast, so I ordered a nebula upgrade. It arrived today, and I attempted to install it…
sigh The first sign of something not right is that when I disconnect the print head and power up, I get nothing on the screen - no splash, nothing. The fans power up, but no display. Not sure if this is normal behavior or not, but I suspect not as I used to have a TAZ 4 and it powered up fine without a print head. Fingers crossed, I went ahead and installed the nebula and powered up… and it splashed properly… but it won’t home (says home failed, and to reset the printer). At this point, I’m suspecting my RAMBO got fried as well. Any pointers?
EDIT: To confirm, the controller board on the TAZ Pro is still a RAMBO, correct?
EDIT2: Actually, I might start with these fuses first:
There’s three 5 and 15-amp standard automotive-style fuses on the board you can check first, and find replacements at any auto part store. They’re the likely ones to fail by shorting the wires to the heater in the head.
Update: upon examining the fuses, it appears both 5A fuses were blown, the 15A fuse appears to be intact. I’ll drop by the auto parts store today to pick up 2 5A fuses, hopefully that will resolve this
Dropped by the auto store on the way home today and replaced those two fuses. It homes properly now Will try a test print when I install the other upgrades
Finished the updates… and it’s not working. The new toolhead does not lower E1 during the bed leveling, causing it to fail. E2 lowers successfully, but E1 stays in-place, which causes it to completely miss the felt during the wiping phase, then miss the washer during the leveling phase. Do I need a new board, or is there another cause that may be doing this? It heats up the nozzle appropriately… I think the only failure here is the raising/lowering of the extruder… and I’d have to guess it’s possible that the extruder is defective, but I don’t know that because of the above issues possibly damaging things
You can try manually telling the machine to swap by sending T0 and T1 commands in the terminal, or selecting 1 or 2 in the Change Filament menu. If there’s no movement that way either, that should rule out problems with your GCODE.
The wiring for the solenoids is pretty far from the hot end, so I don’t think that would be the issue. More likely it’s some plastic that fused the toolhead into position. Check the entire area around the rods for an obstruction, and that the heater block isn’t colliding with the part cooling shroud. You might just remove the part cooling shroud completely to be sure it’s not in the way. If it’s definitely clear, you can swap where the solenoid harnesses that are plugged into the board behind the linear rods and see if that lets the other one move when selecting a toolhead.
Shouldn’t be an issue here - as I said, I replaced the toolhead in its entirety, so this is a completely different toolhead. I guess I’d like to isolate the problem to one of three items:
Defective new toolhead?
Melted wiring from the old harness running to the carriage?
Damaged controller?
You mention possible bad gcode - that’s a possibility too, adding that to the list.
I guess 4 is the easiest to diagnose - hook up a laptop and send the console commands, if it works then the gcode that wasn’t working was bad, everything else in the loop has to be functional if that works.
Ok, I thought you were trying to get the old toolhead working again, not using the nebula.
Have you checked the nanofuses yet? Could be one of those toasted as well.
It’s possible the circuits that drive the solenoid were messed up, but maybe it’s just not connected right at the board on the toolhead mount? Swapping sides for the solenoid harnesses should find that out. If that does remove the toolhead as the problem with movement, check the solenoid wires to the controller for connectivity with a multimeter. If they all check out, swap the solenoid connections at the Archim board to rule out the wiring completely. If solenoid works on the extruder #2 circuit is good, and the wiring for both sides works on the extruder #2 ports on the controller, that really just leaves the controller circuits for #1 to blame.
The board wiring connections should be fine (unless melted somewhere I didn’t see) - I didn’t unseat any connectors on the board. The new toolhead of course was a new connection, I can double check those, but they’re all keyed and kinda hard to mess up.
The nebula does have longer cables (perhaps too long - they impact on the Z rods at the extents, but thus far don’t appear to cause direct problems)… I think I saw they pinouts were different on both side, so I don’t think simply connecting the left to the right would be a good idea (Unless I’m wrong…), and while they are longer… I’m not sure they’re THAT much longer.
Disconnecting and checking voltage might be a dead end - As I recall, one of the early things I saw was that when no tool head was connected (i.e., when I tried powering on the printer after removing the damaged head and before installing the nebula, albeit with two blown fuses at the time), the printer refused to turn on - no splash or interface. I think I’d have to attempt to monitor a live circuit to test.
the Heater block has a wire that connects to the Heater block. When is touches the Any of the 4 corners it send a signal to stop and then go to source speed to touch one of the four corners again if this doesn’t happen, no connection then it throws E1 error. Check the wire that gos to the heater block thru the harness.
I’ve ruled out #4 - selecting 2 on the change filament menu lower the 2nd extruder, but pressing 1 only raises the second extruder, it does not move the 1st extruder. Appears to be wiring, bad tool head, or bad controller
Plug the right-side solenoid from your original Pro Dual toolhead to the connector in place of the left-side solenoid from the Nebula. See if movement happens.
Ok, got home and ran that test - Extruder 2 actually moved properly on the old tool head while plugged into the harness E1, and the new toolhead E2 moved while plugged into the harness E2 - both outputs from the board and both sets of wiring appear to be intact. That appears to narrow the problem down to the new toolhead. Is there any in-house diagnostics I can attempt to get it working here, or should I report it for RMA?
You’d have to contact lulzbot support to see if there’s anything else they’d want to test before having you send it in.
The old dual and the nebula both use the same Acutonix PQ12-100-6-R servos, so you could swap it out if you felt up to it… but as a new toolhead, I’d want it replaced.
Will try a test print when I install the other upgrades