Hi, for a whole year since I built the Prusa i3, I had no major problem. But recently it has been acting very strangely. When I started to print for an hour or so, it would randomly stop.Ts is especially annoying when an object is printed 4-5 hours down the road. I thought it was a problem on the RAMPS board, so replaced it with a brand new one. Added a fan which blow directly at the RAMP board. The problem persists. I commented out the over heat section in the Marlin firmware. Now when it stops, it will give me the Thermo run away error.I have checked all thermistors. And when I install the new RAMPS board, I replaced all wires with new ones and made sure all connections are secured.I also connected the USB to a different laptop to rule out the USB. I can't think of anything else that could cause the problem. Any suggestions? https://reprap.org/forum/read.php?406,607358,607358#msg-607358 Tue, 21 Jul 2026 14:55:51 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?406,607358,639225#msg-639225 https://reprap.org/forum/read.php?406,607358,639225#msg-639225 As it turned out, it was caused by the loose wire from the heat bed connection. Perhaps it's because of the vibrations during printing. once I tighten it up, it works perfectly :)]]> rich1812 Prusa i3 and variants Sun, 13 Mar 2016 17:23:12 -0400 https://reprap.org/forum/read.php?406,607358,608340#msg-608340 https://reprap.org/forum/read.php?406,607358,608340#msg-608340 eatumup Prusa i3 and variants Mon, 11 Jan 2016 20:37:57 -0500 https://reprap.org/forum/read.php?406,607358,608339#msg-608339 https://reprap.org/forum/read.php?406,607358,608339#msg-608339 AudaciousTuddle Prusa i3 and variants Mon, 11 Jan 2016 20:24:04 -0500 https://reprap.org/forum/read.php?406,607358,607460#msg-607460 https://reprap.org/forum/read.php?406,607358,607460#msg-607460
So, check your thermistors and heaters. Make sure they are wired correctly and that temperature swings are not too great. Compare the values to that of known values like room temperature. If they are inconsistent replace them.]]> gmckee Prusa i3 and variants Sat, 09 Jan 2016 23:33:47 -0500 https://reprap.org/forum/read.php?406,607358,607446#msg-607446 https://reprap.org/forum/read.php?406,607358,607446#msg-607446 BSCP(BullSh!!ComputerProblems) have plagued me my whole 40 year career.
For instance:
If you live in a cold country or are printing in the winter and furnace kick[KICKS} on there will be a spike in the mains. Just sayin.
Or air condition in hot climate.

I know people grumble about PC power supplies. But if you wire all the yellows together and wire all the blacks together and wire all the reds together on a surge protected power supply you get a really decent power system. 120VAC @ 32 AMPs. Excuse em wuah?]]> Giantkiller Prusa i3 and variants Sat, 09 Jan 2016 21:55:12 -0500 https://reprap.org/forum/read.php?406,607358,607358#msg-607358 https://reprap.org/forum/read.php?406,607358,607358#msg-607358 rich1812 Prusa i3 and variants Sat, 09 Jan 2016 16:22:23 -0500