PD-Board Issue (Overcurrent/Overvoltage)  

RE: PD-Board Issue (Overcurrent/Overvoltage)

Thanks linkinG the Github. HavinG this issue myselF

Posted by: @thorsten-lachmann

https://github.com/prusa3d/Prusa-Firmware-Buddy/issues/3947

RE: PD-Board Issue (Overcurrent/Overvoltage)

Thanks for this post..... I've been dealing with an over-current issue for months, working with support off and on. They had me do up and then back down in firmware versions, then sent out a new mmu cable that took weeks to get here. I installed the new cable and the error came back after hours and hours of prints and a hard boot. This, as you say, isn't elegant, but it does work. I'm not going to give up on support as this is a know issue and should be fixed. Thanks!

RE: PD-Board Issue (Overcurrent/Overvoltage)

Mine just started doing this error too.   Very frustrating.   We 100% need a permanent solution from prusa here.   Mine is under warrantee so I'm going to send it back under those grounds until a acceptable solution is found.

RE: PD-Board Issue (Overcurrent/Overvoltage)

Having this problem now, too. It's been 100% this afternoon, and it won't start booting properly again until I dis+reconnect the xBuddy cable while it's shut off. Boots up fine the first time, and then if I have to shut it off again for any reason the overcurrent problem happens again. Whether I click the wheel during this error (triggers a reset), hit the Reset button, turn the power off at the PSU, or yank the power cord, I get the MMU overcurrent error every time it starts up. I can tell it's going to happen because during the bootloader screen the fans turn off and the screen blanks and the bootloader starts over.  The only way I can get it to work is to unscrew the top of the MMU, pull the xBuddy cable, reconnect it, and then turn the PSU back on again. At the point the fans turn off, the boot progress indicator continues and the MMU does its boot motions.

I initially shut it down the first time today because between each print it would report a problem with the inserted USB drive (I use the one that shipped with my mk4s), and I thought a reboot might solve that. Then I saw there was a new firmware, so I decided to upgrade. 

In the middle of flashing the printer it does a reboot, and the MMU overcurrent error happened again. I dis/reconnected xBuddy. Then it flashed the ESP, and started without problem-- But then I needed to flash the MMU. So I did, hit the reset button on the front... MMU overcurrent. Pull the cable, reconnect, power on... Booted fine.

This would be a lot less mind-numbingly irritating if the error didn't also trigger a CONSTANT beeping noise.

RE: PD-Board Issue (Overcurrent/Overvoltage)

Amazing response.  Could you simply walk me through the method you are describing here so I can fix mine?  Thanks in advance.

RE: PD-Board Issue (Overcurrent/Overvoltage)

Hello, I have exactly the same problem but I never disconnected the MMU. Just wait three minutes before turning the power back on. When the filament actually gets stuck there is only the option of "retry" no movement, rotation or other option only disassembly.

RE: PD-Board Issue (Overcurrent/Overvoltage)

Posted by: @thorsten-lachmann

for me, I completely fixed that issue and having no more issues or other artifacts since that.

I added a 1Ohms, 1Watt resistor in every red wire (+24VDC) ( so the all over resistance is 0.5Ohms, cause the two red wires are parallely. )

that solution (current limiting resistor) is very common, don’t know, why Prusa didn’t done that for the 24v. For the 5V they did that solution.

current limiting resistors has a lot advantages, if calculated well, in normal condition the resistor has no impact, the voltage drop is here 0.1-0.2v (@24V)

In high current or error behavior that resistor helps to avoid other defects like burned semiconductors….

Greets Thorsten

However, sometimes 30 minutes is not enough, I installed resistors and I don't see the problem.Thanks @thorsten

RE: PD-Board Issue (Overcurrent/Overvoltage)

The issue finally has been properly diagnosed and resolved.  Replace C96 on the xBuddy board with 100nF capacitor.  Prusa has just recently become aware of this but hasn’t yet committed to a course of action.

https://github.com/prusa3d/Prusa-Firmware-Buddy/issues/3947#issuecomment-2665954658

RE: PD-Board Issue (Overcurrent/Overvoltage)

Thank you. Looking forward to a real fix.I'm afraid to turn off my printer and lose access to it.

RE: PD-Board Issue (Overcurrent/Overvoltage)

I have a MK4 with a MK4S upgrade kit then added a preassembled MMU3 upgrade kit and am having the same issue, spoke to Prusa tech support and they sent me a new xBuddy board which worked for one day then it happened again! Couldn't turn the MMU on!

I tried the USB plugged in fix and it worked! haven't used it yet but at least now I can turn on the MMU!

RE: PD-Board Issue (Overcurrent/Overvoltage)

Hi. I have the same problem.How should I proceed please? I also have a MK4s printer.

RE: PD-Board Issue (Overcurrent/Overvoltage)

Looks like Prusa is finally fixing it!

https://forum.prusa3d.com/forum/english-forum-original-prusa-i3-mk4s-general-discussion-announcements-and-releases/6-2-3-alpha-firmware-for-original-prusa-mk4s/#post-739371

RE: PD-Board Issue (Overcurrent/Overvoltage)

Installed and so far no issues after multiple power cycles (on MK4S + MMU3) which usually prompted the issue. 

Promising to see the update!!

RE: PD-Board Issue (Overcurrent/Overvoltage)

It works perfectly for me too. So far on MK4s. But in combination with MK4 I saw that problems are occasional.

But for me perfect work from the Prusa team. I just don't know how long they actually worked on it.

RE: PD-Board Issue (Overcurrent/Overvoltage)

Hi, 

can anyone clarify if the "FIX" by FW is related to a specific Hardware release?

After taking a look to the changes for me the changes will not be working for everyone.
get_board_bom_id() >= 37

https://github.com/prusa3d/Prusa-Firmware-Buddy/commit/365eacb7f2473f974a08a972809a57611e3f751b
Implement safer MMU power on sequence for BOM >= 37BFW-6270

If so, how to find the BOM Id?

RE: PD-Board Issue (Overcurrent/Overvoltage)

Info - Version Info - Buddy Board

RE: PD-Board Issue (Overcurrent/Overvoltage)

I've installed the firmware update (BOM ID: 37) on my MK4S and unfortunately the issue is still persisting. Doesnt seem to be a wirring issue as current because I've rebuilt all the wiring connections and checked resistance/voltage however still receiving overvoltage red screen of death for both the extruder heater and the bed heater. The rest of the printer and functins appear to be working fine however whenever I try to complete an action associated with heating the screen glitches, the heater fan goes to max rpm and the printer displays the red overvoltage screen for either the bed heater or extruder heater.

Cheers, from Australia 

RE: PD-Board Issue (Overcurrent/Overvoltage)

Posted by: @mobbsplanner

I've installed the firmware update (BOM ID: 37) on my MK4S and unfortunately the issue is still persisting. Doesnt seem to be a wirring issue as current because I've rebuilt all the wiring connections and checked resistance/voltage however still receiving overvoltage red screen of death for both the extruder heater and the bed heater. The rest of the printer and functins appear to be working fine however whenever I try to complete an action associated with heating the screen glitches, the heater fan goes to max rpm and the printer displays the red overvoltage screen for either the bed heater or extruder heater.

Cheers, from Australia 

That sounds different from the MMU OVERCURRENT issue.  I’d contact Prusa Support for the problems you’re experiencing.