Hey all, So I just got my first printer working last night, a Prusa Mendel V2 from makerfarm using RAMPS 1.4 and a J-Head hot end (Mk IV I believe). After a couple successful prints, I found that I wasn't getting a reading from my hot end thermistor. Turns out that the glass bead is broken: the top half of the head is gone, exposing the metal inside. I have another thermistor to replace it, but I want to find out the reason the first one broke before frying another. It's very possible there was a short or exposed wire, but I don't know if it would cause the glass to shatter like that. Thanks for the help! Here's a photo of the broken thermistor if it helps: [i.imgur.com] https://reprap.org/forum/read.php?4,286355,286355#msg-286355 Mon, 10 Aug 2026 18:56:32 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?4,286355,287296#msg-287296 https://reprap.org/forum/read.php?4,286355,287296#msg-287296
The hole should be over sized, and a dab of thermal compound should be packed into the hole to help transfer the heat.]]> A2 Reprappers Tue, 31 Dec 2013 17:52:46 -0500 https://reprap.org/forum/read.php?4,286355,287288#msg-287288 https://reprap.org/forum/read.php?4,286355,287288#msg-287288 lazzymonk Reprappers Tue, 31 Dec 2013 17:09:27 -0500 https://reprap.org/forum/read.php?4,286355,286603#msg-286603 https://reprap.org/forum/read.php?4,286355,286603#msg-286603 uncle_bob Reprappers Mon, 30 Dec 2013 09:33:10 -0500 https://reprap.org/forum/read.php?4,286355,286399#msg-286399 https://reprap.org/forum/read.php?4,286355,286399#msg-286399 JayTrinity45 Reprappers Sun, 29 Dec 2013 22:46:44 -0500 https://reprap.org/forum/read.php?4,286355,286381#msg-286381 https://reprap.org/forum/read.php?4,286355,286381#msg-286381 uncle_bob Reprappers Sun, 29 Dec 2013 21:36:50 -0500 https://reprap.org/forum/read.php?4,286355,286355#msg-286355 https://reprap.org/forum/read.php?4,286355,286355#msg-286355 So I just got my first printer working last night, a Prusa Mendel V2 from makerfarm using RAMPS 1.4 and a J-Head hot end (Mk IV I believe). After a couple successful prints, I found that I wasn't getting a reading from my hot end thermistor. Turns out that the glass bead is broken: the top half of the head is gone, exposing the metal inside. I have another thermistor to replace it, but I want to find out the reason the first one broke before frying another. It's very possible there was a short or exposed wire, but I don't know if it would cause the glass to shatter like that. Thanks for the help!

Here's a photo of the broken thermistor if it helps: [i.imgur.com]]]> JayTrinity45 Reprappers Sun, 29 Dec 2013 19:19:04 -0500