So I'm currently working on fixing a Makerbot Replicator 2x.

So I’m currently working on fixing a Makerbot Replicator 2x. My current issue (along with many others I assume) is that when I turn the printer on, the LCD flashes on and off about three times per second, emitting a tone each time it turns back on. We’ve tried removing the SD, and I’m not able to access the help forums due to web filtering at my school. Has anyone had this issue before and if so it would be awesome if you could share your experience.

Thank you so much in advance!
Spyderwillster

@Nathan_Walkner I still get the initial startup noise and then the beep - turn off, turn on - beep - turn off cycle begins

@Nathan_Walkner When you say board do you mean the main board located beneath the printer or the control board with the LCD and button assembly?

Stepper driver could be damaged. Remove them all and add them one by one

Does your school block Google Groups? Try this: https://groups.google.com/forum/#!forum/makerbot-users

A common cause for this is that something is shorted, pulling down the 5v leg, causing the MCU to repeatedly trigger brown-out resets. The X endstop wiring is the most common culprit since it undergoes a lot of flex fatigue (although the cable in the R2x sees this less often than the Rep2 or Rep1 clones since most R2x’s have a flex-ribbon while the previous models use a non-flex ribbon or CD-ROM audio cable with ground on the coaxial shield line).

What you should do is disconnect EVERYTHING from the Mightyboard – stepper drivers, motor and endstop ribbons, LCD, etc. (Take a picture first so you know how it goes back together.) Then plug it in and turn on power and see if it does the reset cycle or not. Then power back off and plug in the LCD and see if you get the firmware startup screen and temperature error from disconnect thermocouples. Repeat with all the components one by one.

FYI, if you plug in the stepper drivers backwards, it will fry the board, so don’t do that. Also, don’t plug or unplug anything with the printer powered on.

@Nathan_Walkner You’d be surprised, an R2x board swap is 2/3rds of the way to building a new printer. All the wiring is special ribbon cables with ferrite beads and junk, and the LCD is incompatible with everything else out there (even Rep1 and clones). At minimum:

  1. You need a board that accepts thermocouples and 24v PSU
  2. You either need a larger PSU or a controller board that has stepper current control configurable in start gcode (IE another Mightyboard or Duet Wifi) so the heater start-up sequence doesn’t cream the stock PSU brick (it’s undersized to run all the heaters and motors at the same time – they use digipots and a staged heatup sequence to keep the current draw down… not a great design decision but they had supply chain reasons back when the R2x was designed)
  3. You have to replace all the XYZ motor and endstop wiring, because it’s on ribbons
  4. You need a new LCD and will probably need to modify the printer’s front-plate to accommodate whatever you swap in
  5. You have to modify the heated bed thermistor circuit, because iirc the R2x has the voltage divider set up differently from RepRap type printers

Once you’re done with all that, unless you put in another Mightyboard, you’re going to have to switch slicers (which may not be feasible for a school with software restrictions) to something that outputs gcode instead of x3g.

The R2x is closed source AND optimized for Makerbot’s supply chain and assembly line, it’s not friendly for major mods at all.

Thanks to everyone that replied, and I’ve identified the issue. We removed the main board cover and found a blown capacitor on the board. We’ll have to get it fixed sometime. Thank you all again for the knowledge and tips, and I will keep your suggestions in mind for future projects!

@Spyder_Willster That’s a blown inductor (L22) according to other board photos I’m looking at. I don’t have any idea how that blew. I’m wondering if the board took a surge through the USB cable. If so, your 8U2 chip (U6 on the silkscreen, used for USB and firmware updates) might be sending reboot commands to the MCU. Could mean the 8U2 is also fried.

900 for that board? That’s insane but MB prices are high. Distributor price for that is about 250 to 300. But yes I would also change it for something else, in my case I’ll do a Cohesion smoothie board from @raykholo

@Nathan_Walkner @Ariel_Yahni_UniKpty Bilby is paying Australia import rates, they’re nuts. Fargo3D in the US can get them a lot cheaper. Still way overpriced though, MBI closed source stock parts are super expensive.

A full transplant to Smoothie or Duet is fine and probably ideal in the long term – it’s a great frame and ok drivetrain – but in the short term, a Mightyboard RevE, LCD, and new wiring harness is cheap and doesn’t require any toolchain changes. If this is a school printer, which is what I gathered from the OP, software changes may actually be a big deal.

Curious on if you ended up replacing that L22. I have the same problem and can tell you exaclty how it happened – I had a USB connected PC powered on, and I tried to attach the power cord 180 deg (upside down). The pins flexed , and made enough contact to fry the inductor.

Fortunate for me the rest of the board seems to have survived. However, the poor inductor is toast.

I’m aiming to get it replaced - does anyone know what its value is supposed to be ?

Image of the toasted board component, on the Makerbot Replicator 2 REV H board. (mightyboard)
https://bayimg.com/faGMgaAbG

Hi @beadon! This is content that was imported to Maker Forums from Google+ when Google shut down Google+ (thus the gplus label), and @Spyder_Willster has not yet logged into Maker Forums, so they won’t get notification of your question, sadly. :frowning: