Is my psu dying?

Lately I noticed that my leds on the X axis are flashing simultaneously with the red led on the hot bed.



They are connected directly to the psu, and the psu I am using is the same 550W psu I got with ormerod 4 years ago.
I disconnected them now cause its hard to be near it from all the blinking

I hope its the psu, and not the board :/

This style Power Supply is built with a thermal restrictive disc current limiter.
Could be this as they go out during normal use most likely nothing else is wrong with the power supply.
They experience all the initial start up power fluctuation and stress of power on's basically protecting the power supply from initial high current startups.
Taking this startup current wears on the component cracking them causing them to be have this intermittent failure.

NTC thermisters are used as ICLs (inrush current limiters) to protect circuits of electrical and electronic devices against inrush currents

This part is simple to replace though it requires the disassembly of the power supply and the removal of the NTC limiting Switch and replacement of a new NTC of same rating.

Determining it is bad is simple as most of the time they will have a distinctive crack in there package.

The NTC limiting Switch Looks like this.




On this supply it is labeled RT1 and is in series with a 6.3amp Fuse.




Edited 3 time(s). Last edit at 03/12/2019 09:49AM by Roberts_Clif.

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Computer Programmer / Electronics Technician

Thanks for the detailed clarification

My psu is a pc psu and I am really not comfortable taking it a part, especially when I never soldered anything in my life.. First I will try to find another PSU just to confirm that it really is the PSU at fault.

It could be that your PSU is dying, but it's more likely that the screws in the VIN terminal block are no longer tight. If it's an Ormerod 1, also check the terminal block in the ATX PSU adapter.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

All the screws on both terminals were tight, but I think I might have found the culprit



This pin is a bit burned, could this be the source of my problem?

I suggest you check the soldering around that pin on the back of that connector too.

I replaced the PSU by a 12V LED/CCTV one, see [www.thingiverse.com].

Edited 1 time(s). Last edit at 03/13/2019 03:13AM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

I actually have one of these laying around, 300W, 12V, 25A, its not fanless, and the fan is pretty noisy
Is a 300W psu really enough for Ormerod 1? Considering I got the printer with a 550W psu.



p.s. I did put "Ormerod 1 owner" in my signature, but for some reson my signature doesnt show :/

A 300W PSU is enough for a dual extruder Ormerod.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

So I had some time and done an inspection of wires and connectors.

I had some burns here, so I re-crimped all the wires and changed the connector.



The back of the ATX PSU adapter looks like this



Wires in the VIN terminals are all tight, nothing loose. The motherboard is all ok, I didnt see anything out of the ordinary.

What I did experience after all the fixes is a momentary drop in power (it just went down for a millisecond but didnt shut down), and once the printer just turned itself off during heating up.

The LEDs stil flicker when the red LED on the heat bed blinks.

Soooo .. could we blame the psu for this? Sadly I dont have any other ATX psu to rule out or confirm that.

EDIT: @DC42 - I am using your sensor kit 2 (or 3) with te IR board, and the LEDs on your board to not flicker, only those connected directly to the ATX psu.

Edited 3 time(s). Last edit at 03/28/2019 03:40PM by Sardi.

Right now it shut down again by itself. No msg on gcode console, just a popup about a communication error.

Quote
Sardi
Right now it shut down again by itself. No msg on gcode console, just a popup about a communication error.

There are two dummy load resistors on the ATX power interface board. Are they still in good condition?

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Got to be honest, I really dont know what a dummy resistor is, but here is a photo of the atx adapter, so if those 1K guys are it, they look good to me.

They are the 22R and 30R resistors at the bottom. They look OK in the photo. OTOH, one of the pins on the white connector looks overheated, as you pointed out earlier.

Edited 2 time(s). Last edit at 03/31/2019 11:23AM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

It does look like that, true. And the soldering on the back is ok. So maybe that is the issue here?
I just turned the printer on after a day of not printing, started heating the bed and hot end, and it shut down again. I didnt mention that when it shuts down, I must unplug the AC cord from the PSU in order to start it up again, I cant just pres 0/I on the PSU and start it up.

Time to get a new PSU I think. I used a Corsair modular 430W ATX PSU for a while, and it was significantly better than the original Alpine one.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

I placed an order for a new PSU, found a good deal for a LC 650W, down from 65e to 50e, going to pick it up today.

Thank you for helping me out Dave, cheers

Just to confirm, it was the PSU at fault. LEDs do not flicker any more.

That's good news.

"I actually have one of these laying around, 300W, 12V, 25A, its not fanless, and the fan is pretty noisy
Is a 300W psu really enough for Ormerod 1? Considering I got the printer with a 550W psu."


I can strongly recommend switching to one of these supplies since your heated bed will warm up very much quicker.
The one I am using also has a fan but is not noisy at all.

The Ormerod doesn't need as much as 300W, however it draws all the power from the 12V rail, and the 550W rating of your ATX PSU refers to the combined load on all the outputs. The maximum load on 12V will only be a proportion of that 550W.

A 12V 300W LED/CCTV PSU is certainly sufficient for an Ormerod. It's what I use to power mine.

Edited 3 time(s). Last edit at 11/25/2019 02:34PM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].