Is my heatbed connected properly?

Hey everyone. I have a heatbed that I haven't been able to find any info on, so any info would be awesome. As you can see in the attached picture, there are 6 solder pads and I don't know if I've soldered to enough of them. The problem it's having is, it barely gets up to 106C with a magazine on top and cardboard underneath. Once I take the magazine off, it drops to around 86C and remains there. So, that's where I'm at. Thanks guys!

Hmmm... haven't seen one like this before. Is there any other writing on it?

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I don't think anything helpful, sorry.

The mk3 is a dual heated bed. There are two separate heating elements. I've not used one myself, but it's discussed here. I think you need to make an additional connection.

I hope you're right, this is perplexing me. So I just somehow need to figure out the other connection(s) without frying something. Am I the only person in the world that has this version? Haha

A little googling will get you your answer. The wiki right here discusses the wiring.

Thanks. I have done a lot of googling and have not found anything about the specific heatbed I have. I've even read that entire wiki you linked to. If anyone could even find a picture of a heatbed with the 6 solder pads like mine (not one of the pictures I posted) I would be very impressed. If anyone can find a picture of it and how to wire it, I would be very happy! Believe me, forums are my last resort, I search like crazy first, google just came up short this time.

Sorry about that. I just saw the mk3 designation. Not the number of pads.

You ought to be able to do some detective work. The mk3 has two heating elements, so an ohm meter should be able to identify which pads are for those. What the other two pads are for I could only guess that they have something to do with the led indicator. Once you know the heating pads (there will be a small non-zero) resistance, you can connect a power supply directly verifying that you get heat. If you do, and you are using 12 volts, then you need to wire the elements in parallel; if you are using 24 volts wire them in series)

No worries mate, I appreciate the help.

I've attached a picture and I hope it's clear. There are 2 ohms between the yellow pads, but only 0.3 ohms between each yellow and red pad and the purple seem to do nothing at all. Unfortunately I will be gone until thursday, but any advice on this between now and then will help me fix it when I get back. Thanks

From your measurements, it sounds that the heated bed has only one element. 2 ohms is a little high for 12V operation, however it sounds that your multimeter probably reads 0.3 ohms with the probes shorted together, in which case tge resistance is really 1.7 ohms. You may get slightly more power if you connect each power wire to both the red pad you have already connected and also to the adjacent yellow pad. The centre pads are a puzzle. Can you tell by following the outline of the PCB traces what they are connected to?

What voltage are you getting between the pads, and how does this compare to the voltage at the output of the power supply?

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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].

Ok, if it's not going to fry anything, I'll connect the other 2 pads and test it. The center pads don't appear to have any traces at all, very weird. The voltage at the power supply is 12.2 and the voltage at the bed is 11.4. It wouldn't be something simple like, not heavy enough gauge of wire to the bed, would it? It is the wire that came with the kit though...

Edited 1 time(s). Last edit at 02/03/2015 11:16AM by gusman.

You will get a little more power if you use heavier gauge wire to the heat bed. It's probably easier to keep the existing wires and run 2 new wires from the electronics to the extra pads. Be sure to label or colour code the wires so that you connect them the right way round.

If the power supply voltage is adjustable, you could turn it up a little.

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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].