Taz 5 Power Supply Issue

Just got a brand new Taz 5 a few days ago and it looks like I got hit with the power supply problem. :cry:

Was in the middle of my fourth print and all power went out. Green light also went out on the power supply. Unit is dead. I just emailed support but was wondering if anyone knew a better way to get ahold of them. I am using this machine to produce a custom bracket for my company and now I am shut down. It seems like this is a pretty big problem with these machines. Is anything being done to address it other then just to replace? Lastly, will Lolzbot do any form of rush shipping? When I ordered the printer it took 7 days to arrive to my local fedex office. I REALLY cant wait that long. I need the option to pay for overnight or second day air. Something! :smiley: Thanks guys! I was really happy with the printer up until the moment it died.

How about calling them?

If you need your power supply replaced, email support@lulzbot.com or call +1-970-377-1111. Phone support is available 7AM - 3:30PM MST Monday through Friday.

Sorry about the inconvenience,


I am actually an engineer so intrigue got the better of me, just popped her open and saw that RT1 is completely cooked. Does anyone have a schematic of the power supply? I am curious what that part actually is :slight_smile:

Dang, I had the exact issue with my Taz 5. I will say that Lulzbot did a great job in getting a replacement out to me. It would have been nice if they over nighted though. :slight_smile: If you look here around the forum there have been multiple reports of Power Supplies dying on the Taz 5. Not sure if the new hotend is pulling more power or what. My recommendation though is to change your start gcode to heat the bed first, then the hotend once the bed is to temp. This will ease the amp draw and help to keep the PS in tact. My replacement PS is already making noise so I figure it’s days are numbered also.


Oh no! Your replacement is already whinning?! That’s not a good sign at all! Has anyone taken a volt meter to the power supply yet to see what the actual current draw is from the wall? When I get my replacement I am planning on doing this for sure. If this thing pulls 10A-12A I would guess that 16A power supply is going to fail rather quickly. Got to leave some room in there. I am already looking for a temporary solution as I run a business from this thing. I found a 24v 20A power supply from Mouser but at $200 its not cheap. Any thoughts about this? Looking at the failed power supply I noticed that both 24v lead wires are tied together so I am assuming this thing runs at just a solid 24v.

Jameco is probably the best place for Power Supplies.

Here’s a couple, there are several more to choose from:



Nice finds on the PSU… after reading so many posts, I figured it might be good to have a backup.


Thanks for the PSU reference! Anyone happen to know what the four pin power supply connector is exactly? Doesnt appear to be for sale on the site.


Ultibots has a Power Supply that should do just fine as a backup or replacement



Check out the powerbox if you use a power supply like that. I did a search on devel.lulzbot.com for source files:

./TAZ/3.1/production_parts/printed_parts/AO_printers/power_supply_cover/powerbox-1.4-skirt-1.0-118s-.5noz-a-PUSHED BACK.gcode

RT1 is a NTC thermistor, being used as a inrush current limiter. It’s a protective element for the PSU. This page explains the general concept. http://en.wikipedia.org/wiki/Inrush_current_limiter

I know this because the thermistor in my PSU just smoked itself.

I think I may have a power supply issue too. My Taz 5 is about a month old so I’m just learning right now. I was printing yesterday and everything was going smoothly until the machine totally reset itself. From then on, whenever I tried to heat the bed or hot end, the machine would reset or the LCD screen would flicker and the internal cooling fan will try to quit until I hit “off” on the heat. The X Y Z axis will no longer move either. The motors make a jittery type sound that makes me think they aren’t getting enough power to move. The power supply is giving off a faint high pitched sounds with no fan movement. That was yesterday. Today when I power up the machine the blue screen backlight comes on but there are no graphics/bootup. I haven’t contacted Lulzbot yet but I will. I figured I would add to this thread and see what you guys thought.

With a new power supply in hand, thanks to the awesome support staff at Aleph, I compared it against the dead one.

RT1 looks to be 5D-15 NTC thermistor, a $2.50 part you can get from Mouser. Although both supplies are nearly identical, there are some subtle differences in component layout.

I believe my old supply was also subjected to a drop at some point prior to delivery, as it had some damage indicators in form of broken plastic screw posts. Further, one of the legs on L1 choke broke at the board, and the inductor itself was at an odd angle with its adhesive bond to the PCB having been broken. I have no idea how this would’ve affected AC filtering, and there are four other legs from the same choke that are fine.

My Taz is humming away on the new supply, and all-in-all, I think I can repair the old one. If nothing else, I’d have an emergency backup on hand if the new supply ever decides to fail once it’s out of warranty.

Sounds similar to how mine went. About 80% through a 10 hour job, the printer seemed to reset, as I found it sitting idle with LCD screen not responding. Power cycled it and restarted the job, and the supply went out during the bed pre-heat.

If your printer is only a month old, you should really drop an email to support@lulzbot.com, or give them a call during business hours at the number on their support page. They will get you taken care of, and from the sound of things, you are not alone with this problem.

Thanks Special-K. I did call them on Monday and they sent me a new power supply. I should have it tomorrow. Really great service. It was nice to pick up the phone and actually talk to someone.

Exactly the same as my original power supply. I had 4 of 6 broke posts on mine, and RT1 failed.

Got my replacement power supply today and I’m back to printing like normal!

My Taz 5 replacement supply just failed.
I’m thinking they need a beefier supply.

I just emailed support to see what to do now.

The power supply unit (PSU) of my Taz 5 just failed after using my 3D printer for a couple of weeks. When I tried to pick the PSU up, the lid came straight off. The 6 poles holding the lid screws were broken. I then realized that component TP1 (apparently a NTC thermistor) was cooked and in pieces. We are currently using the printer at our University to print Drone parts and full Quadcopters. We were having a blast!

I have mailed Lulzbot support and even gave them a call to know what comes next. They replied immediately with a solution. Excellent customer service.

It seems that the thermistor is similar to Mouser’s (http://www.mouser.com) part number number: 954-5D2-15LC or 954-5D2-15LD

For a beefier power supply (24V @ 25Amps) you may consider (http://www.mouser.com) part number: 709-SE600-24 for a little over $90.

I have discovered on my power supply the 12 volt Fan motor was not running. Ordered new, it didn’t work. Checked voltage on board, discovered that the polarity is backwards! Fan would never work as wired from factory. I swapped red/black wires…fan now runs, keeping unit cool enough not to shut down from a thermal overheat issue.