# Need help with my Taz 4 and Firmware **URL:** \ **Category:** Firmware\ **Created:** [January 22, 2026, 2:16am UTC](https://forum.lulzbot.com/t/need-help-with-my-taz-4-and-firmware/27844 "2026-01-22T02:16:48Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![cktechnology](https://avatars.discourse-cdn.com/v4/letter/c/fbc32d/32.png) [@cktechnology](https://forum.lulzbot.com/u/cktechnology)\ **Post date:** [January 22, 2026, 2:16am UTC](https://forum.lulzbot.com/t/need-help-with-my-taz-4-and-firmware/27844/1 "2026-01-22T02:16:48Z")
Hi All, I have pulled my 11 year old taz 4 out from hibernation and i desperately want to get printing. I cleaned it all up, recalibrated, and it did some nice test prints. However, i downloaded the latest firmware from [LulzBot | Downloads](https://lulzbot.com/content/downloads) and installed the 1.0.0.1 firmware. When it rebooted, now it can’t heat the nozzle. I set the nozzle temp but it never heats up. Can anyone tell me where i can get the original firmware that shipped with my taz 4? ---
**Author:** ![Wrathernaut](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.lulzbot.com/wrathernaut/32/13542_2.png) [@Wrathernaut](https://forum.lulzbot.com/u/Wrathernaut)\ **Post date:** [January 22, 2026, 2:48pm UTC](https://forum.lulzbot.com/t/need-help-with-my-taz-4-and-firmware/27844/2 "2026-01-22T14:48:01Z")
> **[Index of /TAZ/4.0/software](https://download.lulzbot.com/TAZ/4.0/software/)** The 1.0.0.1 firmware should be what shipped. ---
**Author:** ![cktechnology](https://avatars.discourse-cdn.com/v4/letter/c/fbc32d/32.png) [@cktechnology](https://forum.lulzbot.com/u/cktechnology)\ **Post date:** [January 22, 2026, 4:07pm UTC](https://forum.lulzbot.com/t/need-help-with-my-taz-4-and-firmware/27844/3 "2026-01-22T16:07:59Z")
Thank you for your prompt reply! Do you know which version based on the screenshot? Also, can someone tell me quickly how to compile into a .hex using the arduino ide? ![image](https://us1.discourse-cdn.com/flex020/uploads/lulzbot/original/2X/b/bdab5b12de8bc27fdd91a79e1523d01f15c4ee6f.png) ---
**Author:** ![Wrathernaut](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.lulzbot.com/wrathernaut/32/13542_2.png) [@Wrathernaut](https://forum.lulzbot.com/u/Wrathernaut)\ **Post date:** [January 22, 2026, 6:41pm UTC](https://forum.lulzbot.com/t/need-help-with-my-taz-4-and-firmware/27844/4 "2026-01-22T18:41:18Z")
They’re versions of Marlin two years apart, so whenever you bought your Mini would align with the firmware that was on it when you received it. You don’t compile the .hex, you send it via CuraLE as a firmware update. ---
**Author:** ![cktechnology](https://avatars.discourse-cdn.com/v4/letter/c/fbc32d/32.png) [@cktechnology](https://forum.lulzbot.com/u/cktechnology)\ **Post date:** [January 22, 2026, 6:52pm UTC](https://forum.lulzbot.com/t/need-help-with-my-taz-4-and-firmware/27844/5 "2026-01-22T18:52:56Z")
Yes I want the earlier one but only the latest is in hex format. The other needs to be compiled onto the hex, correct? ---
**Author:** ![Wrathernaut](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.lulzbot.com/wrathernaut/32/13542_2.png) [@Wrathernaut](https://forum.lulzbot.com/u/Wrathernaut)\ **Post date:** [January 22, 2026, 7:39pm UTC](https://forum.lulzbot.com/t/need-help-with-my-taz-4-and-firmware/27844/6 "2026-01-22T19:39:11Z")
Yeah, you’d need to compile the older one. Dependencies from 2014 code might make it hard to even compile these days though, and where the 1.0.0.1 firmware was used for years in the Taz 4, I would blame your machine before that firmware. ---
**Author:** ![cktechnology](https://avatars.discourse-cdn.com/v4/letter/c/fbc32d/32.png) [@cktechnology](https://forum.lulzbot.com/u/cktechnology)\ **Post date:** [January 22, 2026, 11:15pm UTC](https://forum.lulzbot.com/t/need-help-with-my-taz-4-and-firmware/27844/7 "2026-01-22T23:15:09Z")
ok i found an old firmware and that seems to have set my printer back to normal as far as the look of the UI on the LCD but my extruder STILL is not heating up. Anything else i can check? IT was just working great before i attempted to load the firmware from the lulzbot website. ---
**Author:** ![Wrathernaut](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.lulzbot.com/wrathernaut/32/13542_2.png) [@Wrathernaut](https://forum.lulzbot.com/u/Wrathernaut)\ **Post date:** [January 23, 2026, 12:24am UTC](https://forum.lulzbot.com/t/need-help-with-my-taz-4-and-firmware/27844/8 "2026-01-23T00:24:46Z")
What is it doing when you try heating it? Does it error out? What does the display show around the hot end icon when you try heating it? 0° / 0° or something else? ---
**Author:** ![cktechnology](https://avatars.discourse-cdn.com/v4/letter/c/fbc32d/32.png) [@cktechnology](https://forum.lulzbot.com/u/cktechnology)\ **Post date:** [January 23, 2026, 12:55am UTC](https://forum.lulzbot.com/t/need-help-with-my-taz-4-and-firmware/27844/9 "2026-01-23T00:55:21Z")
So no errors, and the bed heats, but the extruder just stays at room temp. Photo below of the LCD. ![IMG_4849](https://us1.discourse-cdn.com/flex020/uploads/lulzbot/original/2X/0/0c0084e10ef84c62ebf3b15d6d46f8fef0fae595.jpeg) ---
**Author:** ![Wrathernaut](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.lulzbot.com/wrathernaut/32/13542_2.png) [@Wrathernaut](https://forum.lulzbot.com/u/Wrathernaut)\ **Post date:** [January 23, 2026, 1:20am UTC](https://forum.lulzbot.com/t/need-help-with-my-taz-4-and-firmware/27844/10 "2026-01-23T01:20:15Z")
Check the fuses, but also check for voltage at the HEAT0 connector: ![image](https://us1.discourse-cdn.com/flex020/uploads/lulzbot/original/2X/9/9710d0c610c9a580b96a3a74b03aba9052983c26.jpeg) If you have +24v power at that connector when it’s trying to heat the hot end, check again at the toolhead connectors. If there’s voltage there, it would almost certainly be a bad heater. ---
**Author:** ![cktechnology](https://avatars.discourse-cdn.com/v4/letter/c/fbc32d/32.png) [@cktechnology](https://forum.lulzbot.com/u/cktechnology)\ **Post date:** [January 23, 2026, 2:10am UTC](https://forum.lulzbot.com/t/need-help-with-my-taz-4-and-firmware/27844/11 "2026-01-23T02:10:33Z")
Thanks so much for the tip. I’ll check when I get back to office tomorrow. Weird thing is, it was perfect till that firmware flash. ---
**Author:** ![cktechnology](https://avatars.discourse-cdn.com/v4/letter/c/fbc32d/32.png) [@cktechnology](https://forum.lulzbot.com/u/cktechnology)\ **Post date:** [January 27, 2026, 8:08pm UTC](https://forum.lulzbot.com/t/need-help-with-my-taz-4-and-firmware/27844/12 "2026-01-27T20:08:03Z")
Ok so as i thought there is NO voltage on those pins when heating. So its definitely due to the firmware change. The problem is i can’t find the original firmware anywhere except on the SD card but i don’t know how to compile it into a hex. Can someone help me in doing that? I have the Arduino ide installed on my laptop. ---
**Author:** ![cktechnology](https://avatars.discourse-cdn.com/v4/letter/c/fbc32d/32.png) [@cktechnology](https://forum.lulzbot.com/u/cktechnology)\ **Post date:** [January 27, 2026, 8:13pm UTC](https://forum.lulzbot.com/t/need-help-with-my-taz-4-and-firmware/27844/13 "2026-01-27T20:13:34Z")
Sorry i take it back! There is voltage but its not stable its jumping between 16 and 24 ---
**Author:** ![cktechnology](https://avatars.discourse-cdn.com/v4/letter/c/fbc32d/32.png) [@cktechnology](https://forum.lulzbot.com/u/cktechnology)\ **Post date:** [January 27, 2026, 9:22pm UTC](https://forum.lulzbot.com/t/need-help-with-my-taz-4-and-firmware/27844/14 "2026-01-27T21:22:44Z")
Something else i noticed, if is set the hot end to heat, it does heat, just very slowly and temp goes up and down, likely due to that voltage fluctuation. ---
**Author:** ![Wrathernaut](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.lulzbot.com/wrathernaut/32/13542_2.png) [@Wrathernaut](https://forum.lulzbot.com/u/Wrathernaut)\ **Post date:** [January 28, 2026, 4:34pm UTC](https://forum.lulzbot.com/t/need-help-with-my-taz-4-and-firmware/27844/15 "2026-01-28T16:34:12Z")
Failing solder joints for heaters is a known issue with the RAMBO boards. Inspect for charring around those connectors and the solder points to the board. ---
**Author:** ![cktechnology](https://avatars.discourse-cdn.com/v4/letter/c/fbc32d/32.png) [@cktechnology](https://forum.lulzbot.com/u/cktechnology)\ **Post date:** [January 28, 2026, 4:57pm UTC](https://forum.lulzbot.com/t/need-help-with-my-taz-4-and-firmware/27844/16 "2026-01-28T16:57:29Z")
Board looks brand new. I’m pretty sure it’s the firmware ![IMG_4891](https://us1.discourse-cdn.com/flex020/uploads/lulzbot/original/2X/3/3e40379221f7a0bf119ad0da927d3d08a044b108.jpeg) ---
**Author:** ![cktechnology](https://avatars.discourse-cdn.com/v4/letter/c/fbc32d/32.png) [@cktechnology](https://forum.lulzbot.com/u/cktechnology)\ **Post date:** [January 28, 2026, 5:38pm UTC](https://forum.lulzbot.com/t/need-help-with-my-taz-4-and-firmware/27844/17 "2026-01-28T17:38:29Z")
Since I can have two extruders on this model perhaps I can just try the second extruder header? Do you have a layout for this board so I know what each header is? ---
**Author:** ![Wrathernaut](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.lulzbot.com/wrathernaut/32/13542_2.png) [@Wrathernaut](https://forum.lulzbot.com/u/Wrathernaut)\ **Post date:** [January 29, 2026, 4:29am UTC](https://forum.lulzbot.com/t/need-help-with-my-taz-4-and-firmware/27844/18 "2026-01-29T04:29:24Z")
Check the backside of the board here. ![image](https://us1.discourse-cdn.com/flex020/uploads/lulzbot/original/2X/e/e9aad5a1d6995ad1dadf032ae3975ee8cb459e06.jpeg) This spot looks a bit warped and the wire looks a little cooked to me: ![image](https://us1.discourse-cdn.com/flex020/uploads/lulzbot/original/2X/0/055955cd15c1c453b464e719da6a78d2804b4c06.jpeg) Firmware wouldn’t give inconsistent power. Bad solder joints would. The front may look ok, at first glance, but backside is a different story. ![image](https://us1.discourse-cdn.com/flex020/uploads/lulzbot/original/2X/a/affa1139e794cb979028e63c170e9005f0c6e0aa.jpeg) ---
**Author:** ![cktechnology](https://avatars.discourse-cdn.com/v4/letter/c/fbc32d/32.png) [@cktechnology](https://forum.lulzbot.com/u/cktechnology)\ **Post date:** [January 29, 2026, 4:56am UTC](https://forum.lulzbot.com/t/need-help-with-my-taz-4-and-firmware/27844/19 "2026-01-29T04:56:04Z")
Will look tomorrow. Thanks again. For all your help. What is that header for that looks suspicious? ---
**Author:** ![Wrathernaut](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.lulzbot.com/wrathernaut/32/13542_2.png) [@Wrathernaut](https://forum.lulzbot.com/u/Wrathernaut)\ **Post date:** [January 29, 2026, 6:57am UTC](https://forum.lulzbot.com/t/need-help-with-my-taz-4-and-firmware/27844/20 "2026-01-29T06:57:53Z")
It’s the FAN1 header, not one that would typically go out. Probably just a bad injection mold, but the back of the board still needs to be inspected. [Next page](https://forum.lulzbot.com/t/need-help-with-my-taz-4-and-firmware/27844.md?page=2)