I’ll get the part where I did something stupid out of the way first: I was scraping excess plastic off of the bed post-print, and touched the two exposed solder points on the small pcb at the rear of the bed. Yes, the printer was on. Yes, my scraper is metal. The printer turned off and back on when I shorted the contacts.
Now to the symptoms: Upon starting a print, the bed heats to 144 and stays there. The extruder does not start to heat, and nothing else happens. I’m set up to print abs with a bed temp of 110.
Im hoping there’s a fuse somewhere that I’ve overlooked, and that this isn’t going to be an expensive board replacement.
Cheers!
A chip or 2 are fried. Is it actually 144c or is it just reading that temp? Depending on what you shorted, probably blew the power fet for the heater and probably the temp sensor IC.
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In my case I shorted the extruder fan contacts on my Dreamer. I replaced the Main board, which fixed most of the issues, but the heated bed just heated up uncontrollably. I replaced the bed heater, which made no difference. I then replaced the Driver board, which fixed the problem.
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I haven’t read the temp externally to check whether the reading is accurate. By touch, it’s in the ball park. I get 123k across the (cold) thermistor on the bed. It’s rated 100k. I’ve noticed since posting that the bed begins heating as soon as I power the unit on. I also note that when the unit is powered off, and the x or y carriage is moved manually, the lcd screen flickers. I hadn’t notice that before. I’m starting to lean toward a blown voltage regulator. Unfortunately, Flashforge doesn’t publish their schematics, so I’m kind of shooting in the dark if I want to try replacing board components. The stock solution to any electronic issues seems to be: replace the mainboard.
Unlucky, mate! I use a metal scraper so I’ll take your experience as a salutary lesson. So, thanks for that! Chances are, it won’t stop me but hey! LOL
Seems unlikely but, I’d say if it’s actually heating up, you’ve blown the temp sensor
If it’s any consolation it’s a lousy piece of design, expecting surface-mount solder joints alone to support a connector of this size. Any engineer that’s worthy of the name would expect something bad to happen.
ANY OTHER FFCP OWNERS: I suggest you rough-up the areas surrounding the connections on the heater board and stick a dob of JB Weld, high-temp epoxy putty over the solder joints and down onto the board.
Wish I’d have taken my own advice. Just fiddled with it and the heater connection broke at the solder joints! D’ohh!! Time to break out the soldering iron!
Cheers!
Andy
Pot8oSh3d
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Sorry to hear about the connection breaking on you! Once I get the printer running again, I’ll either cover those solder points with a piece of Kapton tape, or power down the printer while scraping (probably both, actually…)
This is excellent! Thanks for this! I can’t look at the files on my phone, but if the schematic is in there, I can at least try replacing some components prior to shelling out for a new MB. Cheers!
Believe that this page MakerBot MightyBoard RevE by MakerBot - Thingiverse will give details about your main board.
You will need to take the bottom off the printer and visually check the board for signs of damage and you might be able to replace the Mosfet that drives the bed heater. Also look in the thing files as it lists the schematic for the board; this with say what component upon the board controls the bed heater. You might find that the short has taken out the main ATMega chip, which can be hard to replace but doable with the right equipment.
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Yes the chips are very cheap if you can handle the surface mount replacement.
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You have blown your FET. DO NOT turn the printer back on until it is repaired. As burnt fet can become a short, and that can turn into a burnt board.
Go immediately to the flashforge google group and search on this very issue.
Do not feel bad about making this mistake. The first search you do there will show people who have done the same, including someone who was cleaning the inside of the FF with a wire brush.
You need to find a friend who can do a surface mount repair, or your local makerspace. Someone who can test it as well.
FETS are cheap. Boards are expensive. PLEASE do not try to use the printer until it is fixed.
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Solder 2 wires on the back of the BP H and see it that works bypass the connector.
