Bed heater keep heating

Hello, i cant control my bed heater anymore.
I start my printer and the bed is starting to heat without any command, i try M140 S0 but no reaction.
I have updated my firmware and web interface with the latest files, when i send the stop command from web interface the heaters go off in the web
interface but the temp on the bed keep going up and it shows to in the web interface. I have a IR temp and the readings in the web interface
and my actual reading is the same +- a few degrees.
The printer head is working as it should.

Only trouble is the bed heater that dont shut off.

Any idea how to get this sorted?

If it worked before and if your E0 heater still does, then I think one of your bed MOSFETs (TR1 or TR2) is broken. If the bed heater is reported to be off on the web interface and yet the bed keeps heating, this would confirm my assumption. In this case I'd contact RRP's support and ask for an exchange.

To confirm this remove the SD-card and start the Duet. If the bed stll heats up then the MOSFET is broken.

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Slicer: Simplify3D 4.0; sometimes CraftWare 1.14 or Cura 2.7
Delta with Duet-WiFi, FW: 1.20.1RC2; mini-sensor board by dc42 for auto-leveling
Ormerod common modifications: Mini-sensor board by dc42, aluminum X-arm, 0.4 mm nozzle E3D like, 2nd fan, Z stepper nut M5 x 15, Herringbone gears, Z-axis bearing at top, spring loaded extruder with pneumatic fitting, Y belt axis tensioner
Ormerod 2: FW: 1.19-dc42 on Duet-WiFi. own build, modifications: GT2-belts, silicone heat-bed, different motors and so on. Printed parts: bed support, (PSU holder) and Y-feet.
Ormerod 1: FW: 1.15c-dc42 on 1k Duet-Board. Modifications: Aluminium bed-support, (nearly) all parts reprinted in PLA/ ABS, and so on.

Unplug the bed from the Duet board and power up the Duet. If the bed LED on the Duet board lights up, it suggests the MOSFET has gone short circuit. If it does not light up, you probably have a short between the bed and ground elsewhere. The MOSFET (TR2) could be changed without replacing the whole Duet, but after fixing and before powering, check that the bed is not short circuit (which could be the reason why the MOSFET blew).

Dave

I got so tired of all problems with Duet and now this and put it away. Now i really need it working and disconnected the bed wires on my Duet board. When i power up the bed led is off and when i shut down it just barely blink one time with very low light, almost as i cant see it.

I have contact between one of the leads and the metal cover the bed heater cables goes in to the bed.

It seems like its the contact on the bed heater that have shorted on the metal plate that is mounted on the bed heater and have melted the isolation on one of the cables.

Need to order spareparts now... don't trust the thing to be on when i am asleep or not at home anymore.....

I have the same problem recently among all sort of issues i see with the ormerod, which is my least reliable printer to be fair.
I would take a silicone heater if i were you.

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----- Making the world smarter @ www.xetal.eu
----- Helping entrepreneurs @ www.fralke.com

Quote
RoSt
I got so tired of all problems with Duet and now this and put it away. Now i really need it working and disconnected the bed wires on my Duet board. When i power up the bed led is off and when i shut down it just barely blink one time with very low light, almost as i cant see it.

I have contact between one of the leads and the metal cover the bed heater cables goes in to the bed.

It seems like its the contact on the bed heater that have shorted on the metal plate that is mounted on the bed heater and have melted the isolation on one of the cables.

Need to order spareparts now... don't trust the thing to be on when i am asleep or not at home anymore.....


[attachment 71448 bedheater.jpg]

That burning is a known issue with the heated bed design used on early Ormerod 2 printers. Suggest you try Emakershop to see if they can supply the newer bed heater and cable that use spade connectors.

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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 wish my printer was as good as this forum and its members.

Silicone heater, any shop you know that sells them?

Is this the later and better version of my bed heater? [www.emakershop.com]

//Robert

a 20x20 shouyld be easy to find. got one made on specs for myself 30x30 from somebody on aliexpress suggested by DC

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----- Making the world smarter @ www.xetal.eu
----- Helping entrepreneurs @ www.fralke.com

Quote
RoSt
I wish my printer was as good as this forum and its members.

Silicone heater, any shop you know that sells them?

Is this the later and better version of my bed heater? [www.emakershop.com]

//Robert

That bed heater isn't the newer Ormerod one, but it may work OK if the wires are long enough. However, geetech doesn't have the highest reputation for quality, and the wires look rather thin to me.

If you have a soldering iron with reasonable power, you can resurrect your old bed heater by soldering wires to the pads on the other side of it.

Edited 1 time(s). Last edit at 02/02/2016 04:59AM 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 have a high quality soldering station but my bed heater is black on both sides and i dont think its possible to get it back to life.

Edited 1 time(s). Last edit at 02/02/2016 07:22AM by RoSt.

Quote
RoSt
I have a high quality soldering station but my bed heater is black on both sides and i dont think its possible to get it back to life.

Happened to mine as well. [forums.reprap.org]
RRP sent me a replacement, though in the meantime I just soldered mine back together with some new wire directly to the topside track, then used a short length of wire to bridge the crater and re-wire the line to the resistor so the LED would work.

As achaz said, you might be able to resurrect the bed by attaching wire links from the underside to the top pads. If you have a Dremel-like rotary tool and one of those wirebrush attachments, maybe you could remove the charred residues from the metal pads (taking care not to obliterate the LED, resistors, or any copper tracks!) to allow soldering the wire links to them? Had a similar issue with my bed, it didn't quite burn as badly as yours though. The wire links stopped any ohmic heating of the pads due to dodgy connections and the bed heats up faster too.

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Bart